Test #2 Flashcards
Quantitative Research
- Seeks explanation or causation
- Objective, precise and measurable outcomes
- Numerical data is collected
- Surveys and questionnaires
- Biometrics (height, weight, bp, pulse, lab results, blood sugar, etc.)
- Data is analyzed using statistics
- Goal is to understand a phenomenon, through:
- Prediction, generalizability (findings from research can be applied in other areas, to other populations), causality (cause and effect)
- Provides research plan (to solving problems, answer questions, test hypotheses)
- Plans control (biases)
confounding variables
Factors/variables that can cause change in the dependent variable that are not a result of the independent variable
Outside factors
conceptual definition of variable
- derived from the literature
- this is how the variable is defined
- Eg. stress = increased heart rate and alertness
operational definition of variable
- translates the conceptual definition into behaviours or verbalizations that can be measured
- this is how the variable is measured
- Eg. measure heart rate
Quantitative: Testability
Measurable
Relationship proposed between X and Y
Is X related to Y?
What is the effect of X on Y?
Theoretical (or Conceptual) Frameworks in Quantitative Research
- Makes the research more rigorous/strengthen quality of study
- A way to understand/explain the research being studied
- Provide an explanation of the relationship(s) between concepts in the study
(Cause and effect, Relationship, Difference) - Guides research (developing research question and hypothesis)
- Operationalizing variables –> how will we measure the variables (instruments?) (we have to measure variables the same way or else the results could be measured incorrectly → bias)
- Understanding results
- Goes beyond a “common sense” explanation
research question
- Research study
- The research question and hypothesis lead to development of a study
- Can only be answered by conducting research in a study
clinical question
- Consumer of Research (EIDM/EBP)
- A clinical question leads to the studies
- Can only be answered by findings in existing research
- Annotated bibliography assignment
Quantitative: Characteristics of a Hypothesis
- relationship between variables is stated
- testable (measurable)
- hypothesis is either supported or unsupported (not proven)
- should state variables, population, and predicted outcomes
- theory based (should flow from research question, literature review to theoretical framework)
- Educated guess
types of hypothesis
research hypothesis (alternative hypothesis) - Statement about expected relationship between variables (causal, directional, non-directional, difference)
statistical (null) hypothesis
- Predicts no relationship; there is no difference
- Rejection of null hypothesis is acceptance of research hypothesis
variable relationships
- associative (there is a relationship)
- causal (one causes the other to change)
- non directional (there is an association)
- directional (same as causal) (one causes the other to change)
- null (no relationship)
- research (same as causal)
critiquing hypothesis
Evaluate the wording for:
- Clarity of statement
- Implications for testability
- congruence/fit with theory/literature
- Appropriateness for research design used
Quantitative Design Purpose
- Objectivity (literature theory)
- Accuracy (study flows from question)
- Feasibility (capacity) (is it possible to do this study?) (time, money, participants, ethics)
- Control (measures used to ensure study conditions remain the same to avoid bias on dependent variable p. 195)
- Control (ruling out extraneous/confounding variables)
- Homogenous sample (the characteristics of participants are similar between groups) (similar extraneous variables)
- Consistent data collection procedures
- Manipulation of the independent variable
- Randomization (equal chance of control or experimental group)
internal validity
- Degree to which the experimental treatment, not an uncontrolled condition, resulted in the observed effects
- Confidence that you have that any change in dependant variable/outcome can be traced back to the independent variable
- Internal validity asks if it’s the independent variable (or something else) that caused or resulted in the change in the dependent variable
threats to internal validity
- history (another specific event affected the DV eg. TV ads)
- maturation (development)
- testing (taking the same test repeatedly could influence outcomes)
- instrumentation (change in observation technique, using instruments properly)
- mortality/attrition (people dropping out of the study)
- selection (how participants are selected)
external validity
Questions the conditions under which the findings can be generalized to the population; deals with the ability to generalize the findings outside the study
threats to external validity
- selection effects (sample size, selection bias)
- reactive effects (Hawthorne effect - Idea that people behave a certain way when they know they are being studied)
- measurement effects (pre/post tests, instrumentation)
sampling
- Sampling is a process of selecting a portion or subset of the designated population to represent the entire population.
- Sample selection based on inclusion and exclusion criteria
- A representative sample is one whose key characteristics closely approximate those of the population.
- Sampling strategies:
Non Probability—non-random
Probability—randomization of sample, more likely to be representative of population review
sampling strategies - non probability
- convenience sampling (people that are most accessible)
- quota sampling (chose based on certain qualities, achieve a sample that represents certain quotas of the population)
- purposive (the researcher selects participants who are considered typical of the population)
- matching (Used to construct an equivalent comparison sample group by filling it with participants who are similar to each participant in another sample group (age, gender, education level, etc)
- network/snowball (For hard to reach populations (eg. drug users)) (A participant in the research helps you find other people to participate in the research)
sampling strategies - Probability
- simple random (Everybody in the population has an equal chance of being selected) (Draw numbers randomly)
- stratified random (Population gets put into homogenous groups (everyone’s the same) and then people are randomly selected from the groups)
- multistage/cluster (selecting clusters/groups that already naturally occur and meet criteria)
- systematic (Randomly choose the first person and then every _th person is selected)
quantitative research designs
- experimental
- quasi experimental
- non experimental/observational
experimental designs
Testing interventions
Cause and effect relationships
Evaluating outcomes (efficacy and cost effectiveness)
Provide level II evidence
experimental study properties
- randomization
- control
- manipulation
inferring causality
1) The causal variable and effect variable must be associated with each other (make sure variables are associated (based on literature) before doing the RCT)
2) The cause must precede the effect
3) The relationship must not be explained by another variable (can’t be an alternative explanation based on another variable)