91影视

We need to describe an experiment using completely randomized design to learn effect of difficulty on estimated time.

Consider:

$30\mathrm{Students}$

Here are two treatments easy maze and difficult maze.

Now, a unique number is between $1\mathrm{and}30$for each student.

A random digit table or a calculator to select $15$unique integers between $1\mathrm{and}30$. The corresponding $15$students are then assigned to the easy mazes.

Then compare the estimates of time worked among the two treatment groups.

We need to describe a matched pairs experimental design using the same $30$subjects.

Consider:

$30$students

Here are two treatments: easy maze and difficult maze.
Let us use two slips of paper and write "$1$" on one slip and "$2$" on the other.
the slips face down on a table and shuffle them.
Let each student randomly select one of the two slips and be sure to return and shuffle the slips around after each drawing.
Students who selected the slip containing "$1$", will first execute easy maze and then execute difficult maze.
Students who selected the slip containing "$2$", will first execute difficult maze and then execute easy maze.
We will then compare the estimates of the time worked among the easy maze and the difficult maze.

We need to explain the difference in the effects of the treatments.

Here,

Match pairs with one subject help reduce the differences in the experiment.