Data from Matthews and Stewart (2009)

Raw data from Matthews, W. J., and Stewart, N. (2009). Psychophysics and the judgment of price: Judging complex objects on a non-physical dimension elicits sequential effects like those in perceptual tasks. Judgment and Decision Making, 4, 64-81.

Files are as follows.

Data from Experiment 1

Columns are as follows

id: participant identifier

trial: trial number

stim: stimulus identifier

price: true price of the presented stimulus

judgment: judged price

rt: approximate time, in milliseconds, between stimulus onset and entry of judgment. Values are unlikely to be accurate. Participants were under no time pressure.

missing: A 1 in this columns indicates that the response was excluded from the analyses. Only two trials were excluded: one because the participant reported making a mistake; another because the value was so large as to be judged an outlier, almost certainly resulting from mis-typing.

Data from Experiments 2a and 2b

Columns are as follows.

feedback: 0 = no feedback (Expt 2A), 1 = feedback (Expt 2B)

id = participant identifier for the relevant experiment. Note that the participants in Expt 2A and Expt 2B were different people, but in both cases they are numbered 1-28.

sex: female=0, male=1

age: age in years

hand: 0=right-handed, 1=left-handed

uk: 0 = participant is from the United Kingdom. Note that all participants had been resident in the UK for at least the past 3 years.

topshop: Had the participant ever visited the shop/website of the shop from which the stimuli were taken? 0 = no, 1=yes.

time: participants’ estimate of time since last visit to the store/website, converted into days – probably not reliable.

block: Trial block. First (8 trials) was practice.

trial: trial number

stim: stimulus identifier

price: price, in pounds sterling, of the stimulus

judgment: participants' judgment of the price. NA means the participant failed to make a response in the allotted time.

rt: Approximate time (in ms) from stimulus offset to entry of response. Values are unlikely to be very accurate. If the participant failed to enter a response in the 3-s window, RT is entered as 0.

missing: A 1 in this columns indicates that the trial was excluded from the analyses. This may be because no response was made, because the participant reported after the experiment that they had made a mistake on a particular trial, or because the judgment was extreme and deemed to be an outlier, perhaps resulting from mis-typing etc.


Jonathan Baron
Last modified: Wed Jun 24 18:48:39 EDT 2009