When digital versions of self-report symptom scales are compared to pen and paper versions , most scales show high interformat reliability .
This supports the reliability of results obtained in psychotherapy research on the Internet and the comparability of the results to traditional psychotherapy research .
BACKGROUND Research on Internet-based interventions typically use digital versions of pen and paper self-report symptom scales .
However , adaptation into the digital format could affect the psychometric properties of established self-report scales .
Several studies have investigated differences between digital and pen and paper versions of instruments , but no systematic review of the results has yet been done .
OBJECTIVE This review aims to assess the interformat reliability of  self-report symptom  scales used in digital or online psychotherapy research .
Validation of the Insomnia Severity Index as a Web-Based Measure
Although the  Insomnia Severity Index ( ISI ) is already administered online , this frequently used instrument has not been vali date d for Web delivery . This study compares online and paper- and -pencil ISI versions completed by participants in a r and omized controlled trial testing an Internet-delivered intervention for insomnia . Forty-three adults with insomnia completed both ISI versions during pre- ( Assessment 1 ) and post-intervention ( Assessment 2 ) . Correlations between total scores of both versions were significant ( rs ≥ .98 , ps < .001 ) . For both ISI versions , internal consistency was acceptable ( Assessment 1 , α = .61 ; Assessment 2 , α ≥ .88 ) . Among participants not receiving the parent study intervention , correlations between 1 format at Assessment 1 and the alternative format at Assessment 2 were generally significant ( rs = .26–.82 ) . Together , findings suggest the ISI can be delivered online
When digital versions of self-report symptom scales are compared to pen and paper versions , most scales show high interformat reliability .
This supports the reliability of results obtained in psychotherapy research on the Internet and the comparability of the results to traditional psychotherapy research .
BACKGROUND Research on Internet-based interventions typically use digital versions of pen and paper self-report symptom scales .
However , adaptation into the digital format could affect the psychometric properties of established self-report scales .
Several studies have investigated differences between digital and pen and paper versions of instruments , but no systematic review of the results has yet been done .
OBJECTIVE This review aims to assess the interformat reliability of  self-report symptom  scales used in digital or online psychotherapy research .