This is one of my pet peeves – and something I have written about in various books. People get focus on ‘technical terms’ and fail to grasp the real meaning. Here is an example I just received in an email from a teacher:
I am wrestling with task validity. It’s regarding a question evaluating the use of lab experiments in terms of validity in comparison with use of questionnaires. Some of my students have written that lab exp may lack task validity but questionnaires have task validity (because lab exp may have a task such as giving electric shocks to a participant but questionnaires are tasks that are not unusual in everyday life). I suppose my query is over this – yes can do a task in lab exp that may lack validity e.g. recalling words from a list to test memory, but in a questionnaire the ‘task’ is the questionnaire (therefore the research method) so is it possible to use the point as ‘task validity’?
I haven’t used the phrase ‘task validity’ but can see what it means. I think the problem often is getting too focused on the terminology rather than the meaning. Yes in an experiment or in fact just an investigation one issue with generalisability is the task that participants are doing which may be rather contrived. I suppose in a similar way any questionnaire requires people to think about what how they might behave or eport their thoughts and this lacks validity because we have no way of knowing whether it really represents how they do behave or what their views really are (they might say they are left wing but not actually think that way). In any exam just saying ‘it lacks task validity’ will gain few marks – the main point is to explain what you mean.
The fact that you don’t do questionnaires in everyday life is totally irrelevant to assessing the value of any research. You don’t do psychology experiments in everyday life but that isn’t relevant to the task validity. Best to try to stop students latching on to jargon terms.