This segment is on "don't know" options. Always a tricky question, should you offer respondents a don't know answer category in the questionnaire or should you not? Howard Schuman and Stanley Presser had in their 1981 book, "Questions and Answers in Attitude Surveys", a nice example here. The question asked respondents on whether they are in favor or opposed to the Agricultural Act of 1978. The interesting thing about this question is that this agriculture act actually didn't exist. So, most people, as you can see in this graph here, they should say don't know because there is no favor or opposed to something that doesn't exist. However, in the first set of bars that you see here, this piece here, the question was asked, just like this, "Are you in favor or oppose?" and there was no filtering out of people that say they have never heard or they don't know what the Agricultural Act of 1978 is. In this condition, we had about 70% who were volunteered the answer don't know. In this other segment here, where first people were asked whether they do know something about the Agricultural Act of 1978, almost 90% said they don't and only the remaining set was asked whether they favor or oppose this particular act. Now there are various methods for offering don't know options. You can have a full filter up front, "Do you have an opinion on that?" or "Do you know about that/" Or you can have a quasi-filter, which is, "Do you agree, disagree, or do you not have an opinion on that?" or "Do you favor or oppose or do you not have an opinion?" And that would be in a formulation for a telephone survey because in self administered mode, obviously, you would have to write down the answer category no opinion, even if it's not part of the questionnaire. Now the question is, should you do this or not? The issue here is, will the respondent be provided with the option "don't know" or do they have to themselves say, "No I don't know anything about this", or "I don't have an opinion"? The views of Converse and Presser is that you should offer to filter out respondents who don't know much and thus can't have an attitude. That was sort of in the 80s, that conclusion from these studies that they did. You can do this and execute this kind of recommendation with filters with increasing strength. So the quasi-filter we talked about, you can have the blunt filter, but you could also have justified full filters. For example, "Have you been interested enough in this to favor one side or another?" or "Have you thought about this issue?", or "Have you heard and read about this issue?" to soften the filtering in case you're worried about that. Now, all these methods aside, Jon Krosnick and actually together with Stanley Presser worked on this later and so more recently the views on using "don't know" option have changed a bit and they are sort of grounded in two cognitive models on the "don't know" response option. The first perception is, we optimize our model in here with the notion that there's four situations in which a respondent might want to say "don't know", along the lines of the response process model. The first one is, so they interpret the question and realize they don't know, which means that the meaning of the question is not clear, right? The search in the memory can be leading to "don't know", which means that there's no information found at all in their head on this topic. The "don't know" can arise, the third step, if they integrate the information into a judgment but in the formulation of their judgment, so there might be ambivalence and conflict among the information that they have in their head or there's insufficient information to justify an opinion. And the last one would be in formulating the answer, so translating the judgment into a response category. And here, it would be that the meaning of the response alternatives is not clear, so they can't really match their thinking to an answer category. And it was only the second step here, the search for memory and "don't know", that really would mean that if you force people into an answer, meaning you don't provide a "don't know" option, they would be giving you a non meaningful answer. So for all of the reasons, except this one, pushing people to offer opinions might yield to meaningful responses. If you take another cognitive model as a baseline here to evaluate these "don't know" responses, that of a satisfying respondent. We'll mention this later again but to point out this term satisficing is from Herbert Simon in the 50s, he described economic behavior with this term, and it's being adopted by Krosnick and Duane Alwin and brought us to match behavior and questionnaire design. So anyway, if we have the satisficer in mind here, who does just enough to sort of get through the questionnaire, then some respondents sometimes look for cues in a question to allow them to skip all interpretation or retrieval to justify the answer. So, you know, I say "I don't know", because I don't want to go through these four steps and think, "Do I understand, can I formulate an answer, can I even retrieve what is in my head?" and the like. So they just pick an easy answer category. Most likely, this behavior might be seen when the respondent's ability to answer that question is low or the respondent motivation is low or there are too high of cognitive demands going on here. So here in this situation, if pushed to offer opinions, these people would offer meaningful opinions and, again, that would be an argument to actually do not offer "don't know" options. There's some experimental evidence out there comparing offering versus omitting "don't know" options. McClendon and Duane Alwin in the 90s, as well as Krosnick and Berent and Poe and others, and I'm sure that there are many more studies of that type, they did years of experiments. They found no more unreliability in responses to unfiltered question than to those filtered. Another set of experiments listed here found that filtering doesn't strengthen constraint correlations between attitudes and different issues. McClendon also, in a later, actually earlier study in 1991, found that filtering did not reduce acquiescence or response order effects. And Krosnick also did a series of studies that supported the notion that by and large, one should probably omit "don't know" options rather than offering them. So, the Krosnick verdict, as we call it here, summarized in those two papers is that "don't know"s are mostly not due to complete lack of information. "Don't know"s are mostly due to ambivalence, unclear questions, intimidation, self-image protection, and satisficing. The best questionnaire design strategy appears to be omitting "don't know" filters and telling respondents, "I'll note that, but if you had to choose, would you say...?" So that could be a way for the interviewer to get substantive response after all, nudging the respondent for an answer and as a result you will be collecting informative data from a larger portion of your sample. Okay and in the next segment we will talk about scales and response order effects in answer categories and the like.
