QUANTITATIVE RESEARCH

METHODOLOGIES

Descriptive Research Chapter Eight

What is Descriptive Quantitative

Research?

? This general category of research designs involves

either identifying the characteristics of an observed

phenomenon or exploring the possible associations

among two or more phenomena.

? In every case, descriptive research examines a

situation as it is.

Descriptive Research Designs

All of these

studies yield

quantitative

information

that can be

summarized

through

statistical

analyses.

? Observation Studies

? Correlational Research

? Developmental Designs

? Survey Research

Observation Studies

? In quantitative research, observation studies are different than observations in qualitative research

? An observation study does not necessarily involve members of the animal kingdom

? A quantified observation study tends to have a particular, pre specified focus

? When humans are the object, the behavior is quantified in some way – behavior may be counted to determine its overall frequency

? In some situations, behavior is rated

? The researcher strives to be as objective as possible

Observation Studies

? Strategies to maintain objectivity:

? Define the behavior precisely and concretely

? Divide the observation period into small segments

? Use a rating scale to evaluate the behavior

? Have two or three people rate the same behavior

independently

? Train the rater(s) to use specific criteria when counting

or evaluating

Correlational Research

? A correlational study examines the extent to which differences in one characteristic or variable are related to differences in one or more other variables

? A correlation exists if, when one variable increases, another variable increases or decreases in a somewhat predictable fashion

? Researchers gather data about two or more characteristics for a particular group of people or other appropriate units of study

Correlational Research

? Whatever the nature of the data, at least two different characteristics are measured in order to determine whether and in what way these characteristics are interrelated

? A scatter plot may be used to allow a visual inspection of the relationship between two variables

? The scatter plot allows us to describe the homogeneity or heterogeneity of variables

? It also allows us to describe the degree to which the two variables are intercorrelated, perhaps by computing a statistic known as a correlation coefficient

? It allows us to interpret data and give them meaning

Correlational Data – Caution

? In all correlational studies, be alert for faulty logic

? We can never infer a cause-and-effect relationship on the basis of correlation alone

? Correlation does not, in and of itself, indicate causation

? A way to explore the dynamics beneath the correlation is through a statistical procedure called structural equation modeling (SEM)

? Another way is to follow up a correlational study with one or more experimental studies to test various hypotheses about what causes what

Developmental Designs

? There are two types of Developmental Designs

? A cross-sectional study, wherein people from several

different age-groups are sampled and compared

? A longitudinal study, wherein a single group of people

is followed over the course of several months or years,

and data related to the characteristic(s) under

investigation are collected at various times

Developmental Desig