Example #1: a Researcher Wishes to Examine Whether Time of Day

question 53

Short Answer

Example #1: A researcher wishes to examine whether time of day (morning versus afternoon) affects the memory of older and younger participants. He obtains a sample of 40 older individuals and 40 younger individuals and gives them a passage to read. They are later given a test over the passage (scores on the test could range from 0 to 30). Half of the individuals are randomly assigned to read the passage and take the test in the morning, and the other half do so in the afternoon. The data are reported in the table below (the numbers represent mean test scores for each group).
$$\begin{array} { | l | c | c | } \hline & \text { Marning Testing } & \text { Afternoon Testirg } \\\hline \text { Older Adults } & \boldsymbol { M } = 15 & \boldsymbol { M } = \mathbf { 8 } \\\hline \text { Yourger Adults } & \boldsymbol { M } = 16 & \boldsymbol { M } = \mathbf { 2 0 } \\\hline\end{array}$$
--Name the other independent variable.
a.Is this IV manipulated or not manipulated by the researcher?
b.Does this IV represent independent groups or correlated groups?
c.How many levels does this IV have?

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Definitions:

Shigeo Shingo

A Japanese industrial engineer known for his influential work in the Toyota Production System and the development of lean manufacturing principles.

Inventory Is Evil

A principle in lean manufacturing and just-in-time (JIT) production that highlights the drawbacks of holding excess inventory, including high costs and potential wastage.

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A financial amount charged for the initial work to configure, prepare, or adjust machinery or equipment for a production run.

Lot Size

The quantity of items that are processed, produced, ordered, or shipped as a batch.