<?xml version="1.0"?>
<informationTable xmlns="http://www.sec.gov/edgar/document/thirteenf/informationtable" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><infoTable><nameOfIssuer>3M CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>88579Y101</cusip><value>446</value><shrsOrPrnAmt><sshPrnamt>4194</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>3894</Sole><Shared>0</Shared><None>300</None></votingAuthority></infoTable><infoTable><nameOfIssuer>AAON INC</nameOfIssuer><titleOfClass>COM PAR $0.004</titleOfClass><cusip>000360206</cusip><value>12370</value><shrsOrPrnAmt><sshPrnamt>448350</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>390125</Sole><Shared>0</Shared><None>58225</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ABAXIS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>002567105</cusip><value>23571</value><shrsOrPrnAmt><sshPrnamt>498118</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>436121</Sole><Shared>0</Shared><None>61997</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ABBOTT LABS</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>002824100</cusip><value>408</value><shrsOrPrnAmt><sshPrnamt>11550</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>11550</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ABBVIE INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>00287Y109</cusip><value>471</value><shrsOrPrnAmt><sshPrnamt>11550</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>11550</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ACACIA RESH CORP</nameOfIssuer><titleOfClass>ACACIA TCH COM</titleOfClass><cusip>003881307</cusip><value>18305</value><shrsOrPrnAmt><sshPrnamt>606718</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>535318</Sole><Shared>0</Shared><None>71400</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ACCELRYS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>00430U103</cusip><value>16652</value><shrsOrPrnAmt><sshPrnamt>1706145</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>1512045</Sole><Shared>0</Shared><None>194100</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ACI WORLDWIDE INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>004498101</cusip><value>28422</value><shrsOrPrnAmt><sshPrnamt>581709</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>505159</Sole><Shared>0</Shared><None>76550</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ADOBE SYS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>00724F101</cusip><value>237</value><shrsOrPrnAmt><sshPrnamt>5450</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>3700</Sole><Shared>0</Shared><None>1750</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ADVENT SOFTWARE INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>007974108</cusip><value>19240</value><shrsOrPrnAmt><sshPrnamt>687878</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>596678</Sole><Shared>0</Shared><None>91200</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ADVISORY BRD CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>00762W107</cusip><value>22261</value><shrsOrPrnAmt><sshPrnamt>423849</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>367879</Sole><Shared>0</Shared><None>55970</None></votingAuthority></infoTable><infoTable><nameOfIssuer>AEROVIRONMENT INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>008073108</cusip><value>7149</value><shrsOrPrnAmt><sshPrnamt>394295</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>351570</Sole><Shared>0</Shared><None>42725</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ALIGN TECHNOLOGY INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>016255101</cusip><value>23047</value><shrsOrPrnAmt><sshPrnamt>687773</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>602473</Sole><Shared>0</Shared><None>85300</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ALPS ETF TR</nameOfIssuer><titleOfClass>ALERIAN MLP</titleOfClass><cusip>00162Q866</cusip><value>239</value><shrsOrPrnAmt><sshPrnamt>13500</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>13500</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ANSYS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>03662Q105</cusip><value>522</value><shrsOrPrnAmt><sshPrnamt>6411</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>6411</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ARCHER DANIELS MIDLAND CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>039483102</cusip><value>222</value><shrsOrPrnAmt><sshPrnamt>6586</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>6586</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>AT&amp;T INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>00206R102</cusip><value>211</value><shrsOrPrnAmt><sshPrnamt>5764</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5764</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>BALCHEM CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>057665200</cusip><value>21467</value><shrsOrPrnAmt><sshPrnamt>488551</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>424751</Sole><Shared>0</Shared><None>63800</None></votingAuthority></infoTable><infoTable><nameOfIssuer>BARD C R INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>067383109</cusip><value>323</value><shrsOrPrnAmt><sshPrnamt>3205</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2555</Sole><Shared>0</Shared><None>650</None></votingAuthority></infoTable><infoTable><nameOfIssuer>BLACKBAUD INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>09227Q100</cusip><value>19598</value><shrsOrPrnAmt><sshPrnamt>661440</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>576140</Sole><Shared>0</Shared><None>85300</None></votingAuthority></infoTable><infoTable><nameOfIssuer>BOTTOMLINE TECH DEL INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>101388106</cusip><value>29295</value><shrsOrPrnAmt><sshPrnamt>1027535</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>903110</Sole><Shared>0</Shared><None>124425</None></votingAuthority></infoTable><infoTable><nameOfIssuer>C H ROBINSON WORLDWIDE INC</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>12541W209</cusip><value>352</value><shrsOrPrnAmt><sshPrnamt>5925</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>4905</Sole><Shared>0</Shared><None>1020</None></votingAuthority></infoTable><infoTable><nameOfIssuer>CARBO CERAMICS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>140781105</cusip><value>14497</value><shrsOrPrnAmt><sshPrnamt>159186</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>137661</Sole><Shared>0</Shared><None>21525</None></votingAuthority></infoTable><infoTable><nameOfIssuer>CHEVRON CORP NEW</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>166764100</cusip><value>695</value><shrsOrPrnAmt><sshPrnamt>5850</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5850</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>CONTANGO OIL &amp; GAS COMPANY</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>21075N204</cusip><value>13781</value><shrsOrPrnAmt><sshPrnamt>343740</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>305240</Sole><Shared>0</Shared><None>38500</None></votingAuthority></infoTable><infoTable><nameOfIssuer>COPART INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>217204106</cusip><value>291</value><shrsOrPrnAmt><sshPrnamt>8500</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>8500</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>CORE LABORATORIES N V</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>N22717107</cusip><value>11665</value><shrsOrPrnAmt><sshPrnamt>84577</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>74127</Sole><Shared>0</Shared><None>10450</None></votingAuthority></infoTable><infoTable><nameOfIssuer>COSTAR GROUP INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>22160N109</cusip><value>38369</value><shrsOrPrnAmt><sshPrnamt>350530</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>305955</Sole><Shared>0</Shared><None>44575</None></votingAuthority></infoTable><infoTable><nameOfIssuer>COSTCO WHSL CORP NEW</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>22160K105</cusip><value>360</value><shrsOrPrnAmt><sshPrnamt>3395</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2580</Sole><Shared>0</Shared><None>815</None></votingAuthority></infoTable><infoTable><nameOfIssuer>CVD EQUIPMENT CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>126601103</cusip><value>201</value><shrsOrPrnAmt><sshPrnamt>19775</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>19775</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>DANAHER CORP DEL</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>235851102</cusip><value>223</value><shrsOrPrnAmt><sshPrnamt>3585</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2285</Sole><Shared>0</Shared><None>1300</None></votingAuthority></infoTable><infoTable><nameOfIssuer>DOLBY LABORATORIES INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>25659T107</cusip><value>391</value><shrsOrPrnAmt><sshPrnamt>11650</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>11150</Sole><Shared>0</Shared><None>500</None></votingAuthority></infoTable><infoTable><nameOfIssuer>DONALDSON INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>257651109</cusip><value>259</value><shrsOrPrnAmt><sshPrnamt>7160</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>7160</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>DU PONT E I DE NEMOURS &amp; CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>263534109</cusip><value>223</value><shrsOrPrnAmt><sshPrnamt>4530</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>4530</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>E M C CORP MASS</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>268648102</cusip><value>250</value><shrsOrPrnAmt><sshPrnamt>10475</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>6875</Sole><Shared>0</Shared><None>3600</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ECOLAB INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>278865100</cusip><value>207</value><shrsOrPrnAmt><sshPrnamt>2585</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>1235</Sole><Shared>0</Shared><None>1350</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ENERGY TRANSFER PRTNRS L P</nameOfIssuer><titleOfClass>UNIT LTD PARTN</titleOfClass><cusip>29273R109</cusip><value>287</value><shrsOrPrnAmt><sshPrnamt>5664</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5664</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ENTEROMEDICS INC</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>29365M208</cusip><value>10</value><shrsOrPrnAmt><sshPrnamt>10000</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>10000</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>EXXON MOBIL CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>30231G102</cusip><value>3977</value><shrsOrPrnAmt><sshPrnamt>44138</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>43738</Sole><Shared>0</Shared><None>400</None></votingAuthority></infoTable><infoTable><nameOfIssuer>FACTSET RESH SYS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>303075105</cusip><value>12591</value><shrsOrPrnAmt><sshPrnamt>135972</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>121772</Sole><Shared>0</Shared><None>14200</None></votingAuthority></infoTable><infoTable><nameOfIssuer>FARO TECHNOLOGIES INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>311642102</cusip><value>18741</value><shrsOrPrnAmt><sshPrnamt>431917</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>378217</Sole><Shared>0</Shared><None>53700</None></votingAuthority></infoTable><infoTable><nameOfIssuer>FASTENAL CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>311900104</cusip><value>425</value><shrsOrPrnAmt><sshPrnamt>8280</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>8280</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>FOREST LABS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>345838106</cusip><value>239</value><shrsOrPrnAmt><sshPrnamt>6270</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5870</Sole><Shared>0</Shared><None>400</None></votingAuthority></infoTable><infoTable><nameOfIssuer>FORTINET INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>34959E109</cusip><value>218</value><shrsOrPrnAmt><sshPrnamt>9190</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>9190</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>GARMIN LTD</nameOfIssuer><titleOfClass>SHS</titleOfClass><cusip>H2906T109</cusip><value>232</value><shrsOrPrnAmt><sshPrnamt>7010</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>6510</Sole><Shared>0</Shared><None>500</None></votingAuthority></infoTable><infoTable><nameOfIssuer>GEEKNET INC</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>36846Q203</cusip><value>155</value><shrsOrPrnAmt><sshPrnamt>10500</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>10000</Sole><Shared>0</Shared><None>500</None></votingAuthority></infoTable><infoTable><nameOfIssuer>GENERAL ELECTRIC CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>369604103</cusip><value>317</value><shrsOrPrnAmt><sshPrnamt>13704</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>13704</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>GENTEX CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>371901109</cusip><value>266</value><shrsOrPrnAmt><sshPrnamt>13290</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>13290</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>GEOSPACE TECHNOLOGIES CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>37364X109</cusip><value>16178</value><shrsOrPrnAmt><sshPrnamt>149908</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>132583</Sole><Shared>0</Shared><None>17325</None></votingAuthority></infoTable><infoTable><nameOfIssuer>GRACO INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>384109104</cusip><value>351</value><shrsOrPrnAmt><sshPrnamt>6047</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>6047</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>GRAND CANYON ED INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>38526M106</cusip><value>13205</value><shrsOrPrnAmt><sshPrnamt>520084</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>461934</Sole><Shared>0</Shared><None>58150</None></votingAuthority></infoTable><infoTable><nameOfIssuer>HANSEN MEDICAL INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>411307101</cusip><value>49</value><shrsOrPrnAmt><sshPrnamt>24500</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>24500</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>HEALTHSTREAM INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>42222N103</cusip><value>17963</value><shrsOrPrnAmt><sshPrnamt>783025</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>694125</Sole><Shared>0</Shared><None>88900</None></votingAuthority></infoTable><infoTable><nameOfIssuer>HIBBETT SPORTS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>428567101</cusip><value>16911</value><shrsOrPrnAmt><sshPrnamt>300539</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>262464</Sole><Shared>0</Shared><None>38075</None></votingAuthority></infoTable><infoTable><nameOfIssuer>HITTITE MICROWAVE CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>43365Y104</cusip><value>19276</value><shrsOrPrnAmt><sshPrnamt>318295</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>279070</Sole><Shared>0</Shared><None>39225</None></votingAuthority></infoTable><infoTable><nameOfIssuer>HOME DEPOT INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>437076102</cusip><value>219</value><shrsOrPrnAmt><sshPrnamt>3135</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>3135</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>IDEXX LABS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>45168D104</cusip><value>216</value><shrsOrPrnAmt><sshPrnamt>2335</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2335</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>IHS INC</nameOfIssuer><titleOfClass>CL A</titleOfClass><cusip>451734107</cusip><value>500</value><shrsOrPrnAmt><sshPrnamt>4770</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>4770</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>INNERWORKINGS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>45773Y105</cusip><value>14550</value><shrsOrPrnAmt><sshPrnamt>961028</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>838953</Sole><Shared>0</Shared><None>122075</None></votingAuthority></infoTable><infoTable><nameOfIssuer>INTEL CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>458140100</cusip><value>268</value><shrsOrPrnAmt><sshPrnamt>12275</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>10175</Sole><Shared>0</Shared><None>2100</None></votingAuthority></infoTable><infoTable><nameOfIssuer>INTERNATIONAL BUSINESS MACHS</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>459200101</cusip><value>1162</value><shrsOrPrnAmt><sshPrnamt>5450</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5450</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>INTUIT</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>461202103</cusip><value>390</value><shrsOrPrnAmt><sshPrnamt>5945</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5045</Sole><Shared>0</Shared><None>900</None></votingAuthority></infoTable><infoTable><nameOfIssuer>IPG PHOTONICS CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>44980X109</cusip><value>411</value><shrsOrPrnAmt><sshPrnamt>6190</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>6190</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>JOHNSON &amp; JOHNSON</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>478160104</cusip><value>553</value><shrsOrPrnAmt><sshPrnamt>6784</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5804</Sole><Shared>0</Shared><None>980</None></votingAuthority></infoTable><infoTable><nameOfIssuer>JPMORGAN CHASE &amp; CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>46625H100</cusip><value>232</value><shrsOrPrnAmt><sshPrnamt>4891</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>4491</Sole><Shared>0</Shared><None>400</None></votingAuthority></infoTable><infoTable><nameOfIssuer>KIMBERLY CLARK CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>494368103</cusip><value>475</value><shrsOrPrnAmt><sshPrnamt>4850</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>4850</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MARKEL CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>570535104</cusip><value>549</value><shrsOrPrnAmt><sshPrnamt>1090</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>990</Sole><Shared>0</Shared><None>100</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MASTERCARD INC</nameOfIssuer><titleOfClass>CL A</titleOfClass><cusip>57636Q104</cusip><value>235</value><shrsOrPrnAmt><sshPrnamt>435</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>305</Sole><Shared>0</Shared><None>130</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MEDIDATA SOLUTIONS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>58471A105</cusip><value>15266</value><shrsOrPrnAmt><sshPrnamt>263300</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>230925</Sole><Shared>0</Shared><None>32375</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MEDIFAST INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>58470H101</cusip><value>7608</value><shrsOrPrnAmt><sshPrnamt>331919</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>297675</Sole><Shared>0</Shared><None>34244</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MERCK &amp; CO INC NEW</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>58933Y105</cusip><value>433</value><shrsOrPrnAmt><sshPrnamt>9800</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>9800</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MERIDIAN BIOSCIENCE INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>589584101</cusip><value>18653</value><shrsOrPrnAmt><sshPrnamt>817562</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>712037</Sole><Shared>0</Shared><None>105525</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MICROS SYS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>594901100</cusip><value>426</value><shrsOrPrnAmt><sshPrnamt>9365</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>9365</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MICROSOFT CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>594918104</cusip><value>239</value><shrsOrPrnAmt><sshPrnamt>8357</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>6537</Sole><Shared>0</Shared><None>1820</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MIDWAY GOLD CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>598153104</cusip><value>32</value><shrsOrPrnAmt><sshPrnamt>26600</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>26600</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MONSANTO CO NEW</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>61166W101</cusip><value>202</value><shrsOrPrnAmt><sshPrnamt>1908</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>1908</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MORNINGSTAR INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>617700109</cusip><value>14946</value><shrsOrPrnAmt><sshPrnamt>213763</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>185788</Sole><Shared>0</Shared><None>27975</None></votingAuthority></infoTable><infoTable><nameOfIssuer>MYRIAD GENETICS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>62855J104</cusip><value>443</value><shrsOrPrnAmt><sshPrnamt>17440</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>16940</Sole><Shared>0</Shared><None>500</None></votingAuthority></infoTable><infoTable><nameOfIssuer>NATIONAL RESEARCH CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>637372103</cusip><value>17480</value><shrsOrPrnAmt><sshPrnamt>302399</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>263982</Sole><Shared>0</Shared><None>38417</None></votingAuthority></infoTable><infoTable><nameOfIssuer>NEOGEN CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>640491106</cusip><value>22797</value><shrsOrPrnAmt><sshPrnamt>459904</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>401680</Sole><Shared>0</Shared><None>58224</None></votingAuthority></infoTable><infoTable><nameOfIssuer>NIC INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>62914B100</cusip><value>23685</value><shrsOrPrnAmt><sshPrnamt>1236161</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>1087736</Sole><Shared>0</Shared><None>148425</None></votingAuthority></infoTable><infoTable><nameOfIssuer>NIKE INC</nameOfIssuer><titleOfClass>CL B</titleOfClass><cusip>654106103</cusip><value>229</value><shrsOrPrnAmt><sshPrnamt>3885</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>3085</Sole><Shared>0</Shared><None>800</None></votingAuthority></infoTable><infoTable><nameOfIssuer>NVE CORP</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>629445206</cusip><value>14228</value><shrsOrPrnAmt><sshPrnamt>252182</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>220963</Sole><Shared>0</Shared><None>31219</None></votingAuthority></infoTable><infoTable><nameOfIssuer>PEPSICO INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>713448108</cusip><value>249</value><shrsOrPrnAmt><sshPrnamt>3150</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2750</Sole><Shared>0</Shared><None>400</None></votingAuthority></infoTable><infoTable><nameOfIssuer>PFIZER INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>717081103</cusip><value>623</value><shrsOrPrnAmt><sshPrnamt>21585</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>21585</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>POLARIS INDS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>731068102</cusip><value>546</value><shrsOrPrnAmt><sshPrnamt>5900</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5900</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>PPL CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>69351T106</cusip><value>271</value><shrsOrPrnAmt><sshPrnamt>8658</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>8658</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>PROCTER &amp; GAMBLE CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>742718109</cusip><value>746</value><shrsOrPrnAmt><sshPrnamt>9676</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>8726</Sole><Shared>0</Shared><None>950</None></votingAuthority></infoTable><infoTable><nameOfIssuer>PROS HOLDINGS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>74346Y103</cusip><value>27329</value><shrsOrPrnAmt><sshPrnamt>1005845</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>870420</Sole><Shared>0</Shared><None>135425</None></votingAuthority></infoTable><infoTable><nameOfIssuer>PROTO LABS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>743713109</cusip><value>29555</value><shrsOrPrnAmt><sshPrnamt>601942</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>530942</Sole><Shared>0</Shared><None>71000</None></votingAuthority></infoTable><infoTable><nameOfIssuer>QLIK TECHNOLOGIES INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>74733T105</cusip><value>316</value><shrsOrPrnAmt><sshPrnamt>12220</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>12220</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>RAVEN INDS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>754212108</cusip><value>32589</value><shrsOrPrnAmt><sshPrnamt>969620</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>842502</Sole><Shared>0</Shared><None>127118</None></votingAuthority></infoTable><infoTable><nameOfIssuer>RITCHIE BROS AUCTIONEERS</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>767744105</cusip><value>10558</value><shrsOrPrnAmt><sshPrnamt>486563</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>419363</Sole><Shared>0</Shared><None>67200</None></votingAuthority></infoTable><infoTable><nameOfIssuer>ROLLINS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>775711104</cusip><value>19129</value><shrsOrPrnAmt><sshPrnamt>779190</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>678260</Sole><Shared>0</Shared><None>100930</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SCHLUMBERGER LTD</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>806857108</cusip><value>234</value><shrsOrPrnAmt><sshPrnamt>3125</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2275</Sole><Shared>0</Shared><None>850</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SCIQUEST INC NEW</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>80908T101</cusip><value>19706</value><shrsOrPrnAmt><sshPrnamt>819719</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>712286</Sole><Shared>0</Shared><None>107433</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SIMPSON MANUFACTURING CO INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>829073105</cusip><value>23337</value><shrsOrPrnAmt><sshPrnamt>762387</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>662437</Sole><Shared>0</Shared><None>99950</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SIRONA DENTAL SYSTEMS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>82966C103</cusip><value>302</value><shrsOrPrnAmt><sshPrnamt>4090</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>4090</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SM ENERGY CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>78454L100</cusip><value>450</value><shrsOrPrnAmt><sshPrnamt>7600</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>7400</Sole><Shared>0</Shared><None>200</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SMUCKER J M CO</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>832696405</cusip><value>590</value><shrsOrPrnAmt><sshPrnamt>5946</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5946</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SOURCEFIRE INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>83616T108</cusip><value>24639</value><shrsOrPrnAmt><sshPrnamt>415984</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>362155</Sole><Shared>0</Shared><None>53829</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SPDR S&amp;P 500 ETF TR</nameOfIssuer><titleOfClass>TR UNIT</titleOfClass><cusip>78462F103</cusip><value>293</value><shrsOrPrnAmt><sshPrnamt>1870</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>1870</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>STAMPS COM INC</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>852857200</cusip><value>19708</value><shrsOrPrnAmt><sshPrnamt>789271</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>693146</Sole><Shared>0</Shared><None>96125</None></votingAuthority></infoTable><infoTable><nameOfIssuer>STERICYCLE INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>858912108</cusip><value>257</value><shrsOrPrnAmt><sshPrnamt>2425</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2025</Sole><Shared>0</Shared><None>400</None></votingAuthority></infoTable><infoTable><nameOfIssuer>STRATASYS LTD</nameOfIssuer><titleOfClass>SHS</titleOfClass><cusip>M85548101</cusip><value>19476</value><shrsOrPrnAmt><sshPrnamt>262408</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>230538</Sole><Shared>0</Shared><None>31870</None></votingAuthority></infoTable><infoTable><nameOfIssuer>STREAMLINE HEALTH SOLUTIONS</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>86323X106</cusip><value>215</value><shrsOrPrnAmt><sshPrnamt>33400</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>33400</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>SUN HYDRAULICS CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>866942105</cusip><value>30138</value><shrsOrPrnAmt><sshPrnamt>927033</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>809959</Sole><Shared>0</Shared><None>117074</None></votingAuthority></infoTable><infoTable><nameOfIssuer>TECHNE CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>878377100</cusip><value>9327</value><shrsOrPrnAmt><sshPrnamt>137468</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>122893</Sole><Shared>0</Shared><None>14575</None></votingAuthority></infoTable><infoTable><nameOfIssuer>TETRA TECH INC NEW</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>88162G103</cusip><value>15207</value><shrsOrPrnAmt><sshPrnamt>498744</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>434969</Sole><Shared>0</Shared><None>63775</None></votingAuthority></infoTable><infoTable><nameOfIssuer>TRACTOR SUPPLY CO</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>892356106</cusip><value>401</value><shrsOrPrnAmt><sshPrnamt>3850</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>3850</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>TRIMBLE NAVIGATION LTD</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>896239100</cusip><value>758</value><shrsOrPrnAmt><sshPrnamt>25300</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>25300</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>TYLER TECHNOLOGIES INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>902252105</cusip><value>28411</value><shrsOrPrnAmt><sshPrnamt>463783</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>406093</Sole><Shared>0</Shared><None>57690</None></votingAuthority></infoTable><infoTable><nameOfIssuer>UNIFI INC</nameOfIssuer><titleOfClass>COM NEW</titleOfClass><cusip>904677200</cusip><value>2918</value><shrsOrPrnAmt><sshPrnamt>152759</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>150759</Sole><Shared>0</Shared><None>2000</None></votingAuthority></infoTable><infoTable><nameOfIssuer>UNION PAC CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>907818108</cusip><value>669</value><shrsOrPrnAmt><sshPrnamt>4700</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>4700</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>UNITED TECHNOLOGIES CORP</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>913017109</cusip><value>279</value><shrsOrPrnAmt><sshPrnamt>2982</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>2982</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>URBAN OUTFITTERS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>917047102</cusip><value>241</value><shrsOrPrnAmt><sshPrnamt>6230</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>5930</Sole><Shared>0</Shared><None>300</None></votingAuthority></infoTable><infoTable><nameOfIssuer>USA MOBILITY INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>90341G103</cusip><value>204</value><shrsOrPrnAmt><sshPrnamt>15350</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>15350</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>VERISK ANALYTICS INC</nameOfIssuer><titleOfClass>CL A</titleOfClass><cusip>92345Y106</cusip><value>598</value><shrsOrPrnAmt><sshPrnamt>9710</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>8710</Sole><Shared>0</Shared><None>1000</None></votingAuthority></infoTable><infoTable><nameOfIssuer>VERIZON COMMUNICATIONS INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>92343V104</cusip><value>347</value><shrsOrPrnAmt><sshPrnamt>7050</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>7050</Sole><Shared>0</Shared><None>0</None></votingAuthority></infoTable><infoTable><nameOfIssuer>WESTWOOD HLDGS GROUP INC</nameOfIssuer><titleOfClass>COM</titleOfClass><cusip>961765104</cusip><value>18160</value><shrsOrPrnAmt><sshPrnamt>408722</sshPrnamt><sshPrnamtType>SH</sshPrnamtType></shrsOrPrnAmt><investmentDiscretion>SOLE</investmentDiscretion><otherManager>
		</otherManager><votingAuthority><Sole>356028</Sole><Shared>0</Shared><None>52694</None></votingAuthority></infoTable></informationTable>
