Case Study

Explain how the symbols XX, ΣX\Sigma X, and NN from the formula conceptually and numerically map onto the design and dataset of this language acquisition study, without completing the final division step.

Case context: A developmental psychologist conducts a small pilot study on language acquisition in toddlers. They record the number of words spoken by five different two-year-olds during a 10-minute play session. The recorded word counts are: 12, 8, 15, 10, and 5. The psychologist wants to find the mean word count for this group using the formula M=ΣX/NM = \Sigma X / N.

Question: Explain how the symbols XX, ΣX\Sigma X, and NN from the formula conceptually and numerically map onto the design and dataset of this language acquisition study, without completing the final division step.

Sample answer: In this study, XX represents the variable of interest, which is the number of words spoken by an individual toddler. The term ΣX\Sigma X represents the summation of all the scores in the dataset, which numerically equals 12+8+15+10+5=5012 + 8 + 15 + 10 + 5 = 50. The term NN represents the total number of scores in the distribution, which conceptually and numerically equals 5 since there are 5 participants in the sample.

Key points:

  • Map XX to the individual word counts of the toddlers.
  • Explain that ΣX\Sigma X represents the sum of all word count scores, totaling 50.
  • Map NN to the total number of scores in the distribution, which is 5.

Rubric: The answer must demonstrate an understanding of the formula components by correctly mapping them to the case details. It should specify that XX is the individual toddler word count, ΣX\Sigma X is the sum of these counts (50), and NN is the sample size (5).

0

1

Updated 2026-05-27

Contributors are:

Who are from:

Tags

KPU

Research Methods in Psychology - 4th American Edition @ KPU

Related