Once you find the exemplar that is similar, you identify it as being a member of the same category ◆i.e. seeing a 4 legged creature, you say it’s a dog bc it looks like at least one other dog you’ve seen before ➔Using the previous study, but with exemplar theory: ◆“A robin is a bird” is verified faster than “a penguin is a bird” ●Could be due to lots of experiences with robins ●With exemplar theory, it’s a numbers game ⇒it’s not because the robin looks similar to your average bird prototype, but because you have many more robin exemplars in your memory than atypical exemplars ⇒you can retrieve the robin exemplar quicker ◆Exemplar theory can equally explain why we respond quicker to more familiar birds ➔Evidence supporting exemplar theory from medical diagnoses ◆Diagnostics categorise a lot ⇒noting symptoms and observations to categorise disease and determine an appropriate treatment ◆Brooks, Norman, and Allen looked at how expert categorisation is influenced by factors relating to prototype and exemplar theory ●Method: dermatologists asked to diagnose patients by observing a series of slides of skin disorders. Two weeks later, they diagnosed a 2nd series of slides and some disorders were repeated, but using different slides ●Question: would the inclusion of a single exemplar 2 weeks earlier improve their accuracy? ○Prototype theory suggests a single case would be blended in averaged prototype ⇒no effect on improving accuracy ○Exemplar theory suggests that any increase in # of relevant exemplars would improve categorisation performance ●Results: on 2nd series, experts were 20% more accurate if they were exposed to a single exemplar two weeks before ⇒experts used the most readily available exemplar ➔Exemplar theory provides a more compelling account for human categorisation abilities, but prototype theory can explain simple categorisation better than exemplar theory
The Development of Categorisation ➔When do we develop the ability to sort new experiences into categories? ◆Children begin developing their categorisation skills during the first few years of life ➔Young children can understand and generalise categories ◆Children as young as 3 are able to understand general categories ●i.e. if you teach a kid a new fact about their pet dog, they can generalise that new fact to different dogs, even if they don’t look similar to her pet ◆Children understand something about category memberships ⇒members of the same categories share similar characteristics ➔Children can understand hypothetical categorisation as well ◆Have a deeper understanding of categories ●i.e. “If I took a toaster, plugged all its holes, but a container in it, and a spout on the side, could it be made into a teapot?” ○They will generally agree it is possible. If you make it so it doesn’t leak, keep liquids warm, and give it a spout, yes. ◆Children have an understanding of the innate properties of a category ●i.e. “If I were to take a raccoon, paint it all black with white stripes down its back, and give it a spray bottle that squirts smelly liquid, can I turn it into a skunk?” ○They will generally agree that this is notpossible ◆
You've reached the end of your free preview.
Want to read all 6 pages?
- Winter '14
- Categorization, Categories, concept learning, Categories & Concepts