Research Control Techniques
This is the most effective way to control participant's characteristics
p 150
What is randomization?
This is the extent to which it can be inferred that the independent variable is causing the outcome
(Polit 153)
What is internal validity?
This is a device that assigns a numeric score to people along a continuum
(Polit 169)
What is a scale?
The extent to which scores are free from measurement error; scores for people who have not changed are the same for repeated measurements. Concerns consistency, the absence of variation, in measuring a stable attribute for an individual.
(Polit 175)
What is reliability?
These four criteria, outlined by Lincoln and Guba, for developing the trustworthiness of a qualitative inquiry, are viewed as the “gold standard” for qualitative research
(Polit 295)
What are credibility, dependability, confirmability, and transferability?
When randomization is not feasible, this method of including only people who are similar with respect to confounding variables is used
p151
What is homogeneity?
As found in quasi-experiments and correlational studies, there are competing explanations for what is causing the outcome
(Polit 153)
What are threats to internal validity?
This consists of several declarative statements (items) that express a viewpoint on a topic; respondents are asked to indicate how much they agree or disagree with the statement
(Polit 170)
What is a Likert scale?
This aspect of reliability captures consistency across items; an instrument is said to have this aspect of reliability to the extent that its items measure the same trait
(Polit 175)
What is internal consistency?
This refers to confidence in the truth value of the data and interpretations of them; parallels to the positivists’ criteria of internal validity
(Polit 295)
What is credibility?
This method of controlling confounding variables involves consciously forming comparable groups
151
What is matching?
This bias, stemming from preexisting differences between groups, arises when people are not assigned randomly to groups, the groups being compared may not be equivalent, leading to group differences in the outcome possibly being caused by extraneous factors rather than by the independent variable. This is the most challenging threat to the internal validity of studies not using an experimental design
(Polit 153)
What is selection bias?
This can be used to measure subjective experiences such as pain or fatigue; it is a straight line, and the end anchors are labeled as the extreme limits of the sensation
(Polit 170-171)
What is VAS or visual analog scale?
The most widely used index of internal consistency reliability yield these, indicating the degree to which the items on a multi-item scale are measuring the same construct; they normally range in value from 0.0 to 1.0, with .80 or higher desirable.
(Polit 176)
What are coefficients, such as Cronbach's alpha?
This refers to the stability of data over time and over conditions; would the study findings be repeated if the inquiry were replicated with the same (or similar) participants in the same (or similar) context? Parallels to the positivists’ criteria of reliability
(Polit 295)
What is dependability?
This is the monitoring of whether or not an intervention is faithfully delivered in accordance with its plan and that the intended treatment was actually received
150
What is intervention fidelity?
This arises from processes occurring as a result of time rather than the independent variable. Wound healing occurs with little intervention, possibly leading to a rival explanation for favorable post treatment outcomes if the design does not include a comparison group. One-group pretest–posttest designs are especially vulnerable to this.
(Polit 153)
What is maturation threat?
An example of a type of closed-ended question
Have you ever been pregnant?
1. Yes
2. No
p 168
What is a Dichotomous question?
This is the degree to which an instrument is measuring the construct it purports to measure; to develop a scale to measure resilience, ensure that the resulting scores reflect this construct and not something similar, such as self-efficacy or perseverance.
(Polit 176)
What is validity?
(not proved or established but rather is supported to a greater or lesser extent by evidence).
This refers to objectivity; concerned with establishing that the data represent the information participants provided and that the interpretations of those data are not imagined by the inquirer. Parallels to the positivists’ criteria of objectivity
(Polit 295)
What is confirmability?
This powerful mechanism controls confounding variables statistically
150
What is statistical control?
The degree to which study results can be generalized to settings or groups other than the one studied; it concerns inferences about whether relationships found for study participants might hold true for different people and settings
(Polit 154)
What is external validity?
These observational sampling methods are a means of obtaining representative examples of observed behaviors; one system involves selecting time periods during which observations will occur and in the other system researchers select integral events to observe
(Polit 173)
What are time sampling and event sampling?
This refers to whether the instrument looks like it is measuring the target construct; it is helpful for a measure to have this if other types of validity have also been demonstrated.
(Polit 176)
What is face validity?
Analogous to generalizability, this is the extent to which qualitative findings have applicability in other settings or groups; the investigator’s responsibility is to provide sufficient descriptive data that readers can evaluate the applicability of the data to other contexts. Parallels to the positivists’ criteria of external validity
(Polit 295)
What is transferability?