# Recent psychophysical studies using the "Method of Adjustment"?

The Method of Adjustment, devised by G.T. Fechner, is one of the three classical psychophysical procedures used to examine perceptual performance.

It came to fame through early studies of visual illusions. But, unfortunately, it is rather difficult to find recent publications in which it was used. Other methods, such as forced-choice procedures, are much more popular nowadays.

### Questions

1. Is there a research field in which the Method of Adjustment is still frequently used, or is even the prevalent psychophysical procedure?

I know that "recent" is imprecise, but I would say that fifty-year old publications do not count as recent, anymore.

### Update (Description of the Method of Adjustment)

The Method of Adjustment, also called Method of Average Error (Guilford, 1954), is used to psychophysically measure a subject's accuracy and precision in matching (subjectively equalizing) stimulus magnitudes.

Typically, subjects are asked to adjust the magnitude of a variable comparison stimulus (Co) until it subjectively equals the magnitude of a fixed standard stimulus (St). This is repeated several times$-$per St as well as for different St's. As a result, one obtains for each St a distribution of Co's. Descriptive statistics of these distributions, such as the mean and the standard deviation, are used to compute the point of subjective equality (PSE) and the difference limen (DL).

A measure of accuracy is the constant error (CE), i.e. the difference between the PSE and the St. A meaure of (relative) precision is the Weber fraction (W), i.e. the ratio of the DL and the St.

• perhaps you should describe the method of adjustment for people who might be able to answer your question but are not familiar with the terminology?
– honi
Dec 8 '15 at 15:55
• @honi: Thanks for the comment. I've updated the post. Dec 9 '15 at 5:47

The recent visual working memory literature has predominately used the method of adjustment. In particular, there is a lot of work using continuous color adjustment tasks:

Wilken P., Ma W. (2004). A detection theory account of change detection. Journal of Vision, 4 (12): 11, 1120–1135.

Zhang, W., & Luck, S. J. (2008). Discrete fixed-resolution representations in visual working memory. Nature, 453(7192), 233-235.

Here's a recent open access paper using the method of adjustment:

Brady, T. F. and Alvarez, G.A. (2015). Contextual effects in visual working memory reveal hierarchically structured memory representations. Journal of Vision. http://jov.arvojournals.org/article.aspx?articleid=2471226

when I was planning a pilot study in which we planned to use cross-modality matching I came across some studies.

1. Human Factors and Ergonomics researchers seem to still use the Method of Adjustment. At least, I found a couple of conference papers in which they examined warning signals for cars. Unfortunately, I don't remember the titles but I think one of the authors was named Baldwin.

2. Try to use Google Scholar or target specific Human Factors and Ergonomic journals (e.g., Human Factor and Ergonomics). You could also have a look at this chapter to follow the references; http://link.springer.com/chapter/10.1007%2F978-3-642-15841-4_1. They used cross-modality matching and the method of adjustment.

I hope that gives you a little hint on where and how to find out more about your questions.

Method of adjustment is still in use in vision science, especially when dealing with illusions. Its major advantage over, for example, 2AFC tasks is the speed of estimation -- you need way less trials to measure the effect, which could be useful in clinical settings [1]. You could also try to search for "nulling" instead of "adjustment" -- nulling is the most powerful variation of the adjustment method, when the subject has control over some aspect of the stimulus and asked to adjust it so as to "null out" the illusion .

It is easy to find such studies with a targeted Google Scholar search, here are some examples:

Maus, G. W., Ward, J., Nijhawan, R., & Whitney, D. (2012). The perceived position of moving objects: transcranial magnetic stimulation of area MT+ reduces the flash-lag effect. Cerebral Cortex, bhs021.

Liberman, A., Fischer, J., & Whitney, D. (2014). Serial dependence in the perception of faces. Current Biology, 24(21), 2569-2574.

Cavanagh, P., & Anstis, S. (2013). The flash grab effect. Vision research, 91, 8-20.

Schloss, K. B., Fortenbaugh, F. C., & Palmer, S. E. (2014). The configural shape illusion. Journal of vision, 14(8), 23.