A lot of information used in aging research relies on self-reports. Surveys or questionnaires are used to assess quality of life, attitudes toward aging, experiences of aging, subjective well-being, symptomatology, health behaviors, financial information, medication adherence, etc. Growing evidence suggests that older and younger respondents are differentially affected by questionnaire features and the cognitive tasks that question answering pose. This research has shown that age-related changes in cognitive and communicative functioning can lead to agerelated differences in self-reports that are erroneously interpreted as real age differences in attitudes and behaviors. The current review highlights how the processes underlying respondents' self-report change as a function of respondents' age; it updates our previous reviews of this literature.Keywords Aging Á Self-reports Á Surveys Á Questionnaires Á Questionnaire features Á Survey methodology A lot of information used in aging research relies on self-reports. Surveys or questionnaires are used to assess quality of life, attitudes toward aging, experiences of aging, subjective well-being, symptomatology, health behaviors, financial information, medication adherence, etc. Over the past 50 years, a strong body of research has uncovered many potential sources of response biases in surveys and has shown that apparently minor variations in question format, question order, or the position of response options can systematically bias responses and lead to false reports of attitudes and behaviors (for reviews see Schwarz 1999a; Sudman et al. 1996;Tourangeau et al. 2000;Abeele et al. 2013;Krosnick et al. 2006). Growing evidence suggests that older and younger respondents are differentially affected by questionnaire features (Schwarz et al. 1999;Yoon et al. 2010). This research has shown that age-related changes in cognitive and communicative functioning can lead to age-related differences in self-reports that are erroneously interpreted as real age differences in attitudes and behaviors. The current review highlights how the processes underlying respondents' self-report change as a function of respondents' age; it updates our previous reviews of this literature (Schwarz 2005;Schwarz et al. 1999;Schwarz and Knäuper 2000). Notably, this review concludes that age-related differences in question or response option comprehension and memory retrieval can lead to erroneous conclusions about age differences in opinions or behaviors. Yet, the examples identified over the last 20 years have not yet led to substantial changes in survey research that systematically address these problems. Also, the available research is still limited in quantity and quality, as detailed below.