Measure of dream recall frequency: Comparing retrospective and logbook evaluations

Abstract

Dream recall frequency (DRF) is the main indicator for evaluating dream. In home-setting, DRF can be established using two major methods: the retrospective estimation (RE) and the logbook estimation (LE). No research to date has compared DRF obtained with these two methods on the same period and using an online logbook that does not allow rereading of previous reports. We aim at investigating on these two methods by evaluating their influence on the recall frequency of dream (DRF).
In the present study, the protocol consisted of online questionnaires in order to prevent rereading: an initial RE, a LE for a 21-day period, and a final RE. Both RE were based on an open-ended question about DRF on the last 21 days. Thus, the score of DRF assessed with the LE and the post-logbook RE were established on the same period.

In line with the literature, our results revealed that the score of DRF with the pre-logbook RE was significantly inferior to the score of DRF obtained with the LE. However, the score of DRF with post-logbook RE was not different to the score obtained with LE. Our preliminary results are discussed by suggesting that disparities existing between Pre-logbook RE and LE might be undermined by other factors than methods influence on DRF. We recommend that further methodological comparisons should cares about effects of period investigated and influence of rereading on memory.