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
