The quality of survey measurements is a main topic of survey research. When interpreting survey data, survey researchers always have to deal with possibly biasing response effects like acquiescence or question order effects, i.e. with problems of validity and reliability. Another possible source of survey bias is the use of different survey modes which could lead to different kinds or sources of biasing factors in response behavior.
As a special type of paradata, unobtrusive measurement of response latencies has the potential to give researchers insights into cognitive processes which are activated while respondents answer to survey questions (e.g. analysis of accessibility of mental associations or the depth of information processing).
In this paper, quality of attitude scales (in terms of reliability, validity, and strength of response effects) are analyzed in a comparative approach, analyzing data of web surveys and a CATI study using the same attitude scales. These attitude scales consist of negative and positive worded items, allowing the analysis of acquiescence effects which are expected to be stronger when respondents answer spontaneously, i.e. when response latencies are fast.
Estimating multiple group and interaction structural equation models, the paper helps to answer questions (1) whether web survey and CATI data are differently or equally biased by response effects, and (2) whether respondents' behavior is identical or not comparing both survey modes. Additionally, from a methodological perspective, it is possible to (3) compare the power of response latency as moderator of data quality of web versus telephone surveys.