Quantitative Research Methods

Descriptive or Survey Research

Studies phenomenon/issues and problems as they exist at one point in time. It involves making careful descriptions of the phenomenon in language and literature. It is concerned with “what is.”

Characteristics of a descriptive or survey research

• information is collected from a group of people in order to describe some aspects or characteristics such as abilities, opinions, attitudes, beliefs, and/or knowledge of the population of which that group is a part
• information is collected through asking questions; the answers to these questions by the members of the group constitute the data of the study
• information is collected from a sample rather than from every member of the population

Purposes of Descriptive Research

• presents description for purposes of policy formulation
• helps in improving existing conditions

Types of Descriptive Research

• Longitudinal study – involves collecting data from a sample at different points in time in order to study changes or continuity in the samples’ characteristics.
• Trend Studies – describe change by selecting a different sample at each data collection point from a population that does not remain constant
• Cohort Studies – describe change by selecting a different sample at each data-collection point from a population that remains constant
• Panel Studies – this involves selecting a sample at the outset of the study and then at each subsequent data-collection point surveying the same sample is done
• Cross-sectional studies– the data are obtained at one point in time, but from groups of different ages or at different stages of development

*Cross-sectional survey – collects information from a sample that has been drawn from a predetermined population. The information is collected at just one point in time, although the time it takes to collect all the data desired may take anywhere from a day to a few weeks or more.

Types of Instruments in Descriptive or Survey Research

Questionnaire  – this is a type of instrument in which the respondents are asked to express their views, opinions, or knowledge using a scale.

Types of Questions

The nature of the questions, and the way they are asked, are extremely important in the research survey:

• Closed-ended questions are easy to use, score, and code for analysis on a computer. Since all subjects respond to the same opinions; standardized data are provided.
• Open-ended questions– allow for more individualized responses, but they are sometimes difficult to interpret.  They are also often hard to score since so many different kinds of responses are received.

Kinds of Questionnaire

Postal questionnaires –this involves sending of ‘self-completion’ questionnaire through the post. This involves coverage of a large geographical area.

E-questionnaire – this involves sending of ‘self-completion’ questionnaire through email or other electronic means. This also has a large geographical area coverage.

Interview

A measure that specifies the questions to be asked of each research participant, the sequence in which they are to be asked, and guidelines for what the interviewer is to say at the opening and closing of the interview.

Kinds of Interview

1. Face to face interview – allows a direct interface between the research or data gatherer and the respondent.
2. Telephone interview – uses the phone to gather data from the respondents.  Other prefer a telephone interview because it is cheaper and faster than the face-to-face interview.

Correlational Research

A type of investigation that seeks to discover the direction and magnitude of the relationship among variables through the use of correlational statistics.

Purposes of Correlational Research

• to clarify our understanding of important phenomenon through the identification of relationships among variables
• to predict a score on either variable if a score on the other variable is known

Scattergram or Scatter Plot

It is a pictorial representation of the correlation between two variables.  The scattergram tells the type of correlation evident between the two variables.

• Perfect correlation
• Positive correlation
• Negative correlation
• Absence of correlation

Casual-Comparative or Ex-post Facto

It determines the cause, or reason for existing differences in the behavior or status of groups.

Experimental Research

This provides a systematic and logical method for answering the question of what will happen if experiments are done in carefully controlled conditions. In this study, the researchers manipulate certain stimuli, treatments, or environmental conditions and observe how the condition or behavior of the subject is affected or changed.

Types of Experimental Designs

Pre-experiment. It is the least adequate of designs are characterized by: (1) lack of a control group; (2) failure to provide for the equivalence of a control group.  Some examples of pre-experimental designs are:

1. One-shot case study design – a type of experimental design in which an experimental treatment is administered and then a post-test is administered to measure the effects of the treatment.

2. One-group, pretest-posttest design – a type of experiment in which all participants are exposed to the same conditions; measurement of the dependent variable (pretest), implementation of the experimental treatment, and another measurement of the dependent variable (posttest)

3. Static–group comparison design – this design compares the status of a group that has received an experimental treatment with one that has not.  There is no provision for establishing the equivalence of the experimental and control groups. In some books, this design is classified under the quasi-experimental design.

4. Solomon four-group design – a type of experiment involving two treatment groups and two control groups, so that the researcher can determine the effect of both the treatment variable and the pretest on the dependent variable.

Tests in an Experimental Research

• Pre-test – a measure that is administered prior to an experimental treatment or other intervention
• Posttest – a measure that is administered following an experiment or control treatment or other intervention in order to determine the effects of the intervention

Groupings in an Experimental Research

• Control Group – a group of research participants who receive no treatment or an alternate treatment so that the effect of extraneous variables can be determined.
• Experimental Group – a group of research participants who receive treatment

Focus of experimental research

• Controls. Experimental research focuses on the ‘manipulation of circumstances.’
• Identification of causal factors. It helps in identifying which factor actually causes the observed outcome to occur.
• Observation and measurement. It should be precise and detailed.