Question

Consider the study looking at the impact of people’s income (middle-class vs. wealthy) and personality (extrovert vs. introvert), on two distinct outcomes (people’s life-satisfaction and health). Now, define the term ‘main effect’. How many main effects would this study have? What findings / results / group differences would each of the main effects describe or pertain to? Be specific?

Answer 1

Main effect is generally used in analysis of variance. The definition of main effect is, "It is the effect of an independent variable on a dependent variable averaged across the levels of any other independent variables."

Considering the study Middle class vs wealthy, Extrovert vs. Introvert with the outcome people's life satisfaction and health, the study can possibly have two main effect namely,

Extra money/Income/free money and

Extra Time/Reduced work time

The way the population belonging to the groups middle class, wealthy, extrovert, introvert respond to the extra money they have and the extra time they have shall give new situations and characterisitcs that shall yield various forms of outputs. All those can be correlated and statistically analysed to identify how the extra time and extra money is utilized to achieve happiness and good health.

The groups and the conditions can be framed in the following way for an effective investigation.

Group 1: Middle class people with extra money

Group 2: Middle class people with extra time

Group 3: Middle class people with extra time and extra money

Group 4. Wealthy people with extra money

Group 5: Wealthy people with extra time

Group 6: Wealthy people with extra time and extra money

Group 7: Introverts with extra time

Group 8: Introverts with extra money

Group 9: Introverts with extra time and money

Group 10: Extroverts with extra time

Group 11: Extroverts with extra money

Group 12: Extroverts with extra time and extra money

Without the extra money and extra time it shall be difficult for the middle class people to explore more, the same is applicable for the wealthy people, but in other ways. Similarly, the extroverts and introverts lives are also affected by extra time and extra money, The former shall use either one of them or both to party, make friends and relax while the later shall find an alternative at home or venture as a lone wolf.

Group 1 to group 6 shall be used to investigate to obtain results for Middle class vs Wealthy people. The extra time and extra money shall have strong influence in various other variables such as friends, family relatives, hobbies, travel, etc. These shall directly or indirectly affect the health and happines of the individual.

Similarly, group 7 to group 12, shall be used to ivestigate to obtian results for Extroverts and Introverts.