The Impact of Stimulus Presentation and Size on Preference

Moore et al. (2017) compared two ways of showing items in an MSWO preference test. One way used the exact item the caregiver named. The other way used a standard size for every item.

They ran five head-to-head tests to see if the two methods gave the same top three favorite items.

The top three items matched in three of the five tests. The big difference showed up lower on the list. Less-preferred items swapped ranks when the size or look of the stimulus changed.

Bottom-line: keep the picture or object the same each time or you may reshuffle the middle and bottom tiers.

Laugeson et al. (2014) saw the same kind of drift. They changed how long kids could touch the item instead of how it looked. Longer access gave steadier rankings, but the very top items still stayed put.

Miranda et al. (2023) looked at another MSWO detail—where items sit on the table. They found almost no positional bias, meaning kids did not just pick the right-side item every time. Together these three studies say: tiny set-up choices can nudge lower-tier ranks yet rarely flip the clear favorites.

Heinicke et al. (2019) reviewed pictures, videos, and verbal lists as options to real objects. They warned that switching modality without checking prerequisite skills can also reorder preferences. The Moore finding now gives single-case proof for that warning.

For day-to-day practice, pick one stimulus format and stick with it for the whole assessment cycle. If you swap from a big bag of chips to a tiny photo between sessions, you risk moving medium-preferred items up or down. That error can lead you to pick the wrong backup reinforcers or miss a new favorite. Keep size, photo angle, and texture constant and you will get cleaner, more useful preference stacks.