Ambulatory assessment of language use: Evidence on the temporal stability of Electronically Activated Recorder and stream of consciousness data.

The ambulatory assessment offers a wide range of methods enabling researchers to investigate psychological, behavioral, emotional, and biological processes. These methods enable us to gather data on individual differences in language use for psychological research. Two studies were conducted with an aim to evaluate and compare the temporal stability of language measures extracted by LIWC software form data obtained by two frequently used methods for assessment of language use, i.e., Electronically Activated Recorder (EAR) and stream of consciousness (SOC) task. Additionally, we examined the amount of variance in language use (assessed by both methods) that can be attributed to intra-individual variability and stable individual differences. Study 1 was focused on investigating language use obtained from 74 respondents using the EAR for 3 consecutive days. Study 2 was conducted on 250 respondents participating in a SOC task where verbal production was collected at ten time points over a 2-month period. Results show that measures obtained using the SOC task have higher temporal stability and consistency, and to a certain extent enable better detection of individual differences. Taking into account certain situational variations improves the reliability of EAR measures.