Manipulative skills
Use this page to explain that we are interested in the difference between the groups and, in particular, the difference between the group means, . However this difference is random, so we must understand its distribution before we can interpret its value.
The simulation is based on a real data set, but only mention that the difference between the model's group means is µ2 - µ1 = 2.20 pins. Take several samples and mention the variability in the difference between the sample means. (The light blue bands for each group are µ ± 2σ.)
Now select Actual data set from the pop-up menu.
To interpret what the difference between the sample means tells you about µ2 - µ1, you must understand its distribution.
Manipulative skills
To test the manipulative skill of job applicants, they are sometimes given a 'one-hole test' in which they grasp a pin, move it to a hole, insert it, and return for another pin. The test score is the number of pins inserted in a fixed time interval. A large study was undertaken comparing male college students with experienced female industrial workers. The table below describes the number of pins inserted in one minute.
Group | n | mean | s |
---|---|---|---|
Male college students | 750 | 35.12 | 4.31 |
Experienced female industrial workers | 412 | 37.32 | 3.83 |
The simulation uses these values as population parameters.
Welders who are paid a salary and those on piecework
This example is described in the diagram