very . ▁ ▁The ▁research ers ▁acknow ledge ▁that ▁some ▁strength s ▁are ▁more ▁difficult ▁to ▁assess ▁than ▁others , ▁therefore ▁methods ▁of ▁assess ing ▁these ▁strength s ▁are ▁still ▁in - progress . ▁ ▁For ▁each ▁strength , ▁there ▁are ▁typically ▁several ▁measures ▁that ▁could ▁be ▁admin ister ed ▁in ▁order ▁to ▁assess ▁a ▁person ' s ▁trait ▁level ▁for ▁that ▁strength . ▁▁ ▁Time ▁and ▁energy , ▁however , ▁prohib it ▁admin ister ing ▁all ▁of ▁the ▁measures ▁for ▁the ▁ 2 4 ▁strength s ▁in ▁one ▁testing ▁session . ▁ ▁To ▁solve ▁this ▁problem , ▁Pet erson ▁& ▁Sel ig man ▁designed ▁a ▁new ▁measure , ▁the ▁VI A - IS , ▁to ▁assess ▁all ▁ 2 4 ▁strength s ▁in ▁relatively ▁brief ▁amount ▁of ▁time . ▁ ▁Begin ning ▁in ▁the ▁fall ▁of ▁ 2 0 0 0 , ▁the ▁research ers ▁pilot ▁tested ▁the ▁VI A - IS ▁with ▁a ▁group ▁of ▁ 2 5 0 ▁adult s . ▁ ▁The ▁research ers ▁removed ▁items ▁that ▁correl ated ▁poor ly ▁with ▁the ▁rest ▁of ▁the ▁items ▁in ▁the ▁same ▁scale ▁of ▁interest . ▁ ▁Pet erson ▁& ▁Sel ig man ▁repeated ▁this ▁process ▁until ▁C ron bach ' s ▁alpha ▁for ▁all ▁scales ▁exceed ed ▁. 7 0 . ▁ ▁Al ong ▁the ▁way , ▁the ▁research ers ▁added ▁in ▁ 3 ▁reverse - sc ored ▁items ▁in ▁each ▁of ▁the ▁ 2 4 ▁scales ▁as ▁well . ▁ ▁For ▁the ▁current ▁version ▁of ▁the ▁VI A -