Lecture 9: Quantitative Methods, Measurements and Sampling 2 Flashcards
what is the only way you can talk about causal relationships?
in the context of a true experiment
what does a true experiment require?
- at least two groups
- there is a randomization of participants to each of the two groups
- a control condition (one of the two groups is a control condition)
what’s the difference because “cause and effect” and “correlation”
cause and effect: there’s a factor that causing things to happen
correlation: two things are happening at the same time
what is a Quasi-Experimental Research Design?
- studies that are “sort of” experimental in design
- no randomization to groups
- low on internal validity but often higher in external validity
what is the ‘‘basic formula’’ for a quasi-experimental study?
- people are studied in real-world settings
- an independent variable is introduced or manipulated
- there is a dependent variable (the effect) that is measured
when is a pre-experimental research design used?
when true experiments and quasi-experimental designs are not possible
what does a pre-experimental design do?
- often used as a prequel or pre-cursor to randomized control trials
- pre-experimental designs pose challenges to internal and external validity
feasibility and pilot studies can be conducted to?
improve the chances of conducting a high-quality RCT
what is a feasibility study?
used to assess whether a planned main study can be done, and the practicality of the study elements
what is a pilot study?
a type of feasibility study that is a small-scald and -scope preliminary test of whether the critical elements of the main study will be feasible
what is construct validity?
are you actually measuring what you think you’re measuring
what characterizes a non-experimental research design?
- no randomization to groups
- no groups to randomize to
- no manipulation of the independent variable
what is a non-experimental research design used for?
to report correlations among variables of interest
how can data collected in quantitative studies be described as?
- discrete
- continuous
- nominal
- ordinal
- interval
- ratio
what is discrete data?
a count involving integers
ex. 206 people in a class
what is continuous data?
data that is continuously being taken
ex. heart beat
what is nominal data?
type of discrete data, describes a category
ex. sex, blood type, eye colour
what is ordinal data?
type of discrete data, values that provide a classification
ex. placement for a race or weight status category (overweight, underweight, etc.)
what is interval data?
a type of continuous data, spacing between numbers, the amount of change between numbers is the same no matter what the numbers are
ex. temperature (5-10 degrees is the same at 80-85 degrees difference)
what is ratio data?
a type of continuous data, classification using an ordered continuum with equal intervals and a true zero
ex. height, weight
what are the data collection methods?
- observation (watch)
- measurement (assess)
- questioning (ask)
what are the observation (watch) techniques?
- direct- participant is aware of researcher’s presence
- indirect- film or videotape is used
- participant- research is part of the research situation
what are the measurement (assessing) techniques?
- physical measures (ex. BMI)
- cognitive measures (paper and pencil tests)
- affective measures (opinions, attitudes, emotions) (ex. perception of risk COVID-19)
what are the questioning (asking) techniques?
- structured / unstructured questionnaire (ex. 24-hour movement behaviors)
- checklist (ex. dietary intake)
- structured / unstructured interview (ex. interview guide / scripted questions and prompts)
- Delphi Technique = consensus view of subject experts
