1. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Hidden mixed-mode design in catering survey Godenhjelm, Petri 1, Siikanen, Antti 1,Saarni, Kaija, 2 Honkanen, Asmo 2 & Ahvonen, Anssi 2 1,2 Statistics Finland 2 Finnish Game and Fisheries Research Institute Montréal ICES III 2007

2. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Structure of the presentation Catering sector Mixed-mode surveys Design Material and methods Results Discussion

3. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Catering sector Catering sector here: meals served outside households, restaurants, personnel canteens, schools, hospitals etc. Value of daily consumer goods in Finland was in 2005 about 21 mrd. euros Share of catering sector is 5 mrd. euros Every third Finn eats daily meals served by catering sector

4. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Mixed-mode surveys Mixed mode surveys is used more and more budgetary reasons non response reasons different populations have different communication preferences data quality reasons respondent friendly reasons use of telephone has changed (technological and cultural) Still not enough is known about implications to survey results validity and comparability between survey results of different modes Visual and aural modes Business surveys might include also some opinion and attitudinal questions in which mode effects are more common

5. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Design Paper questionnaire was sent before CATI interviewees gathered data Paper questionnaire was sent with the contact letter In the contact letter caterings were asked to get acquainted with the questionnaire and fill it as much as it was possible But not to send the paper questionnaire because CATI interviewee would take contact to them It was obvious that not all respondents were filled the questionnaire at the time of CATI contact

6. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Hidden-mixed mode There could exist an hidden mixed-mode situation about which researcher might not easily be aware of In literature called as a concurrent multiple mode system A screening question was designed to the end of CATI interview : Has a respondent filled the questionnaire beforehand 1) totally 2) almost totally 3) partly 4) not at all ?

7. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Mode of answering The assumption in the screening question: those who answered totally were answering to a paper questionnaire those who answered not at all were answering to a pure telephone interview Middle categories also gave some interesting knowledge about how respondents react to a survey contact

8. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Data Survey population Finnish caterings (14 740) Stratified sample 2263 Stratified by amount of served meals in a catering Response rate 80 % (n=1741) Telephone interviews by CATI

9. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen The distribution of the screening question Totally31 % Almost totally23 % Partly15 % Not at all 31 %

10. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Different questions were measured Attitudinal questions : statement type questions about the use of fish and attitudes to fish in catering Questionnaire included also questions about amounts in kilograms and origin The questionnaire was divided into three sections for fish, crayfish, and game (red deer, moose, reindeer) A Chi-Square Tests were done with different questions Contingency tables were analysed

11. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Shares of strongly disagree responses to the statements on answering mode Significant (p <0.05) differences in 11 out of 12 statements in battery

12. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Comparability problem Different modes produce different results How to control survey design process ? Should data be adjusted some how ? Risks to misinterpretation Mixed-mode experiments clearly show that survey answering is social interaction and communication with different senses (visual vs. aural)

13. Godenhjelm, Siikanen, Saarni, Honkanen & Ahvonen Remarks Human aspects behind survey results play an important role Knowledge of mixed-mode surveys is crucial in making sensible survey strategies Effects in attitudinal vs. factual questions Mixed-mode vs. non response Unimode or mode-spesific data collection strategy ?