▁Ad van cement ▁of ▁Science ▁( AA AS ) ▁benchmark s ▁with ▁links ▁to ▁relevant ▁online ▁resources . ▁NS DL ▁mines ▁metadata ▁of ▁collections ▁to ▁find ▁online ▁resources ▁that ▁match ▁the ▁benchmark s . ▁ ▁The ▁collections ▁m ined ▁are ▁chosen ▁based ▁on ▁criteria ▁proposed ▁by ▁a ▁National ▁Research ▁Council ▁Ste ering ▁Committee ▁for ▁Develop ing ▁a ▁Digital ▁National ▁Library ▁for ▁Under grad uate ▁Science , ▁Mathemat ics , ▁Engineering , ▁and ▁Technology ▁Education ▁ ▁and ▁the ▁valid ity ▁checked ▁regularly . ▁Te ach ers ▁find ▁Ph ET ▁sim s ▁that ▁are ▁appropriate ▁for ▁specific ▁topics ▁by ▁searching ▁the ▁maps . ▁ ▁M ER L OT ▁Physics ▁▁ ▁uses ▁a ▁tier ed ▁review ▁process ▁to ▁evaluate ▁digital ▁learning ▁content . ▁Ph ET ▁was ▁featured ▁as ▁a ▁Show case ▁in ▁June ▁ 2 0 1 3 ▁where ▁teachers ▁can ▁find ▁teaching ▁and ▁learning ▁resources ▁that ▁includes : ▁Link s ▁to ▁Member - Selected ▁Learning ▁Material s , ▁Pe er ▁Re views ▁of ▁High ▁Qu ality ▁Material s , ▁and ▁Te aching ▁Exper ien ces ▁of ▁M ER L OT ▁M embers . ▁Physics ▁Front ▁ ▁is ▁a ▁" free ▁service ▁provided ▁by ▁the ▁A AP T ▁in ▁partners hip ▁with ▁the ▁NS F / NS DL " ▁that ▁has ▁about ▁ 1 0 0 ▁ideas ▁for ▁using ▁Ph ET ▁with ▁editor ▁reviews , ▁recommended ▁subjects , ▁levels , ▁resource ▁type , ▁appropriate ▁courses , ▁categories ▁and ▁ratings ; ▁ideas ▁for ▁use ▁in ▁units , ▁correlation ▁to ▁AA AS ▁standards ; ▁and ▁related ▁activities .