STAT 5303 Assignment 8

An Investigation of Socioeconomic Factors on Verbalization Skill

A study was designed to evaluate whether socioeconomic factors had an effect on verbalization skill of young children. Four socioeconomic classes were defined and 20 children under the age of six were selected from each class for the study. The research hypothesis was that the mean verbalization skills would be different for the four classes. The researchers determined that for young children there may be significant gains in verbalization skills over only a few months. Thus, they decided to record the exact age (in months) of each child. The verbalization skills (measured by testing) were determined for each child. A description of the variables appearing in the dataset along with abbreviated names is as follows.

  1. Age: Age (months).
  2. Verbal: Verbal skill score (higher values correspond to greater skill).
  3. Class: Socioeconomic class (1=low, 2=middle, 3=upper-middle, 4=upper).

Using these data, build an ANCOVA model to compare verbal skill among the four socioeconomic classes, while controlling for age. Specifically, provide complete answers to the following questions: