Introduction
Causal-comparative research is a technique that involves the determination of cause or consequences of the differences that exist between two or more groups. In this approach, two or more groups are examined and the possible cause, effects, or consequences of the differences between the groups are identified. This approach helps to identify associations that exist between variables.
Activity 16.1
In this activity, some questions would lend themselves well as causal-comparative research. One of them is “which subjects do high school students like least?” This question evaluates the effects of being a high school student. For example, girls would end up disliking a science subject because their performance is not as a good as of the boys. The other question that comes out well is “Are two-year-old girls aggressive than two-year-old boys?” which explores the cause. The answer to the question can be positive or negative depending on differences in gender of the children observed.
Activity 16.2
- Experimental vs. Causal-comparative
- A study by Stanford University concerning the starting salary for college graduates who majored in either computer science or communication is causal-comparative. The main reason being that the differences between the two groups already exist as the study is conducted.
- However, the study on 1500 men and women with exceptionally high levels of amino acid homocysteine is an experiment. Alongside the study, an experiment is carried out. A sample of the population studied is given vitamin B supplements to support the outcome of the research.
- The research on genetic modification of Bt corn is experimental
- New Zealand study that found no relationship between years of education and income is causal-comparative
- Research on soccer and swimming is causal comparative
- The study of breast cancer is causal-comparative
Causal comparative studies do not involve an experiment to manipulate any variable. The researchers have based their comparison on existing differences between the variables.
- Groups studies from 1a to 1f above.
- computer science majors and communications majors
- 1500 men and women
- Bt corn
- Swimmers
- 20000women
Discussion Question
- A suitable comparison group for a researcher investigating delinquent behavior in teenagers would be those who come from affluent families and those who come from poor families.
- Observation can be used in causal-comparative studies to make a comparison. For example, the technique can be used to collect data when studying aggressiveness of two-year-old boys and girls.
- A research might prefer to conduct a causal-comparative study rather than an experiment when resources are fewer because an experiment is expensive. A good example is testing the effect of a new treatment on a serious disease.
- Questions that might lend themselves better in a casual comparative research are those that explore cause, effects or consequences.
- A causal-comparative study would be easier to conduct than an experiment. A causal-comparative study is cheaper because it does not require manipulation of variables.
- Random selection is a technique that involves how a sample is selected from the population. Random selection is not possible in a causal comparative study because groups are already formed.
- Effects of team teaching on student attitudes towards history can use causal-comparative research. The research can compare two groups where one is inspired on importance of positive attitude on the subject, and the other is not involved in any motivation at all.
- Unlike in experiments, there is no manipulation of variables in causal-comparative research. However, the researcher can control the dependent variable.
- A researcher can study same variables in an experiment as a causal-comparative study. The research need to manipulate the independent variable in an experiment.
- Quantitative variables that should not collapse include; age of a person, self-esteem or GPA. A quantitative variable that can justifiably be viewed as categorical is creativity.
- Eating disorder is likely to be the cause higher incidence of childhood sexual abuse. Other contributing causes could be neglect of family.
- Causal comparative study looks at questions that only bring comparison among variables. These questions address cause, effect or consequences of the differences.
- I would recommend she use causal-comparative. It is more convenient and affordable. Using her on instrument would not make any difference in the recommendation.
Identifying Types of Sampling
For each of the situations described below, identify the type of sampling that is being used:
1. A researcher is interested in interviewing a group of New York City police officers. She goes to the main precinct in Manhattan and asks for volunteers to be interviewed. The researcher then pays for the interviews. Convinience sampling
2. A researcher is interested in interviewing all the members of the New York City police force who do not live in the city. He gets a roster of the names of all officers on the force, randomly selects five police stations, and then conducts interviews of all officers in those stations. Cluster sampling
3.A researcher is interested in interviewing alumni of San Simeon College who graduated between the years 1990 and 1996. He gets the roster of the names of these individuals from the alumni office and mails a questionnaire to everyone on this roster. No sampling—entire population is being studied
4 Another researcher is also interested in interviewing alumni of San Simeon College who graduated between the years 1990 and 1996. He gets the roster of the names of these individuals from the alumni office, selects the names of 100 individuals who graduated during these years using a table of random numbers, and then mails a questionnaire to everyone selected. Simple random sampling
5. A researcher is interested in identifying the attitudes of the physicians who work for Keyser Hospital toward the Republican plan for health care. She obtains a list of all the Keyser Medical Centers in Southern California and randomly selects ten of these Centers. Then she obtains a list of all the physicians at these Centers and randomly selects eight physicians from each Center to interview. Two-stage random sampling
6. A graduate student enrolled in the Marriage and Family Counseling Program at Daytona University is interested in determining how other graduate students feel about the program. He interviews all of the students he has access to on a given Monday night when he takes one of his counseling courses. Convenience sampling
7. A student enrolled in the Hotel and Restaurant Management School at Colorado State is researching the best restaurants in Denver based on the opinions of food critics. She begins by asking her advisor who refers the student to four food critics who have written extensively on the subject and whom the student then contacts to interview for her study. Purposive sampling
