Researchers studied frequency and amount of alcohol use in three groups of students (grades 6 to 8, grades 9 to 10, and grades 11 to 12) over five years. With this , researchers can examine age-related changes and changes within the same individuals as they age. In addition, researchers can account for the possibility of cohort and/or time of measurement effects.

cross sectional study

Explanation:

cross sectional study is defined as a kind of observational research that analyzes data of variables collected at a given point in time across a sample population. It is also used to determine if exposure to specific risk factors might correlate with particular outcomes. An example is a medical researcher collecting cross sectional data on a patients past smoking habits and current diagnosis of lung cancer. They are also called Transverse or Prevalence study

answer; john b watson,(observable behavior);