Which scales can you use?
Questionnaires often use scales to measure respondents' opinions but also to look at what they did. However, you can also use scales in observations, logs, tear-off cards, and interviews.
Which scales are there?
There are several different scales you can use, and they all give slightly different information.
- 2-point scale: yes/no
- 3-point scale: a lot/little/not at all or yes/neutral/no
- 4-point scale: totally disagree/disagree/agree/ totally agree
- 5-point scale: totally disagree/disagree/no opinion/agree/fully agree or 5 stars (from very dissatisfied to very satisfied)
- 10-point scale: a report mark from 1 to 10
Which scale do you choose?
- With the 2-point scale, respondents must fill in extremes; it is either yes or no. This scale gives a very clear picture, and there is no middle ground. Sometimes respondents find this difficult, as people prefer to keep a low profile or add more nuance. Only use this scale when it's about a straightforward yes or no, like with questions about behavior: you have or have not visited a museum.
- The 3-point scale allows respondents to choose extremes but also to answer neutrally. However, when often responding neutrally, this does not yield much for the survey. Also, use this scale especially when asking about behavior: How often do you drink coffee? Not - sometimes - every day
- With the 4-point scale, there is no room for neutral answers, and respondents have to make a choice. It does allow for some nuance, which respondents like. This scale is used when you ask for an opinion, and you want them to choose.
- Another option when asking for opinion or attitude is the 5-point scale. Respondents like this scale because it allows for nuance and provides a middle ground if they cannot or do not want to choose. You can broaden a scale to 7, but that gives the illusion of more distinction, while you can't interpret that. Since this scale is very frequently used, respondents and readers of your research will understand this scale. The five-point scale allows you to present a range of statements that collectively measure something. This gives you a good idea of the opinion or attitude of respondents about a particular subject. When putting together the theories, you need to pay attention to the validity and coherence of your theories.
- The 10-point scale has a broad division between very bad and excellent and everything in between. Everyone is familiar with report cards; however, the disadvantage is that there are some differences in interpretation in the details. Everyone agrees that up to 5 is insufficient, but what is the difference between an 8 and a 9? In addition, some people never give a 10 because perfect does not exist, while others give a 10 if they think it is very good. So this scale gives respondents a lot of room to add nuance, but it is difficult to define. Only use this scale if you want to compare your score with other scores or with scores from previous measurements. In that case, ask for a general grade and express the different parts on a different scale.