Title |
The power law repealed: The case for an exponential law of practice
|
---|---|
Published in |
Psychonomic Bulletin & Review, June 2000
|
DOI | 10.3758/bf03212979 |
Pubmed ID | |
Authors |
Andrew Heathcote, Scott Brown, D. J. K. Mewhort |
Abstract |
The power function is treated as the law relating response time to practice trials. However, the evidence for a power law is flawed, because it is based on averaged data. We report a survey that assessed the form of the practice function for individual learners and learning conditions in paradigms that have shaped theories of skill acquisition. We fit power and exponential functions to 40 sets of data representing 7,910 learning series from 475 subjects in 24 experiments. The exponential function fit better than the power function in all the unaveraged data sets. Averaging produced a bias in favor of the power function. A new practice function based on the exponential, the APEX function, fit better than a power function with an extra, preexperimental practice parameter. Clearly, the best candidate for the law of practice is the exponential or APEX function, not the generally accepted power function. The theoretical implications are discussed. |
X Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 2 | 67% |
Unknown | 1 | 33% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Scientists | 2 | 67% |
Members of the public | 1 | 33% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 13 | 4% |
Netherlands | 6 | 2% |
Germany | 3 | <1% |
United Kingdom | 3 | <1% |
France | 2 | <1% |
Australia | 2 | <1% |
Brazil | 2 | <1% |
Spain | 2 | <1% |
Belgium | 1 | <1% |
Other | 3 | <1% |
Unknown | 325 | 90% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Ph. D. Student | 90 | 25% |
Researcher | 66 | 18% |
Student > Master | 36 | 10% |
Student > Bachelor | 29 | 8% |
Student > Doctoral Student | 21 | 6% |
Other | 75 | 21% |
Unknown | 45 | 12% |
Readers by discipline | Count | As % |
---|---|---|
Psychology | 137 | 38% |
Engineering | 33 | 9% |
Computer Science | 22 | 6% |
Neuroscience | 19 | 5% |
Agricultural and Biological Sciences | 16 | 4% |
Other | 65 | 18% |
Unknown | 70 | 19% |