Glossary Vocabulary Flashcards
All vocabulary in the glossary is game on exams!
Primary hypothesis
The tested hypothesis for which an experiment is powered. It is the effect of the independent variable on the dependent variable.
Secondary hypotheses
(there could be several); Oftentimes other effects of an I are examined, but the hypothesis is not necessarily powered to state an effect statistically.
One-sided hypothesis or one-tailed test
you assume the DV will move in one direction.
Two-sided hypothesis or two-tailed test
You don’t know if DV will go up or down
Null hypothesis (Ho)
A statistical concept which states there is no effect of the IV on the DV, it is often credited as the primary test and if structured properly ensures no pre-conceived bias and fulfills the notion of randomness
Independent Variable (IV)
what the investigator controls/manipulates to produce a change in the DV
Dependent Variable (DV)
What the IV effects; i.e. what you measure
Confounding Variables
Known factors that disrupt or influence the effect of the IV on the DV that should be recognized prior to the initiation of an experiment
random error
is an inherent aspect of measurement which increases variability and reduces the ability to detect differences among groups.
Positive Control
is a group added to a design where you know what the outcome will be and the outcome is expected to move in the direction you think the independent variable should move it.
Negative Control
is a group added to a design where you know the outcome, but unlike the positive control, you know what the IV will not affect the group
epiphenomenon
a result that accompanies another, but has no causal influence itself or was not caused by the experimental paradigm
Vehicle control
(injectate or pill without the test substance). This has everything you are administering except the level of the IV.
Sham control
(generally associated with a surgical intervention where a mock surgery is performed). A form of procedural control
Procedural control
(running the same procedure without the active intervention). This generalized control procedure would include sham controls, which is a special case of procedural control but is outside of the realm of surgery.
Repeated measures
will use the subject as its own control of alternatively in a non-repeated measures design, using one side of the animal as a control for the other.
Hypothesis Driven Research
in which a specific hypothesis is laid out upfront and then tested prospectively.
Prospective studies
a study where a hypothesis is formulated and then tested after the design has been laid out
Retrospective studies
that assess the effect of an IV on a DV after the fact; after the IV effect on the DV has occurred. These are commonly used in clinical studies
discovery research
formulates the basis for hypothesis driven research. It generally involves mining data sets or output to determine if a relationship will emerge so that a hypothesis can be formulated
clinical trial
a study on patients that is always prospective and tests a very specific hypothesis generally about a drug or specific type of intervention. it is the most rigorous (from a control perspective) type of clinical research.
cohort study
is a study of a group of subjects that shae something in common, and are assessed as they move forward in time.
cross-sectional study
is similar to a cohort study except that all the measures are taken at the same time (once) and these are always retrospective studies.
case-control studies
are similar.ar to cross-sectional studies. Thus, the PI identifies a group of patients with the disease and another without the disease and looks back at their behaviors that may have contributed to the disease.
Ethnographic research
Study of human behavior in its natural context, involving observation of behavior and physical setting. Can be both pro- and retrospective.
Explanatory research
Where the experimenter attempts to identify cause and effect. Cause and effect assume that we identify the actual cause of something.
Historical research
The systematic collection and evaluation of data related to past occurrences (retrospective) in order to describe causes, effects, and trends of those events that may help explain present events and anticipate future events.
Quasi-experiment
is an empirical study used to estimate the causal impact of an intervention on its target population. Quasi-experimental research designs share many similarities with the traditional experimental design or randomized controlled trial, but the specifically lack the element of random assignment to treatment or control.
Prevention Trials
Look for better ways to prevent disease in people who have never had the disease or to prevent a disease from returning.
Screening Trials
Test the best way to detect certain diseases or health conditions.
Diagnostic trials
conducted to find better tests or procedures for diagnosing a particular disease or condition.
Treatment trials
test experimental treatments, new combinations of drugs, or new approaches to surgery or radiation therapy to determine which is better.
quality of life trials (supportive care trials)
explore ways to improve discomfort and the quality of life for individuals with chronic illness.
Compassionate use trials (expanded access trials)
provide partially tested, napproved therapeutics to a small number of patients who have no other realist options. Usually, this involves a disease for which no effective therapy exists or a patient who has already attempted and failed all other standard treatments and whose health is so poor, he does not qualify for participation in randomized clinical trials. Usually, case-by-case approval must be granted by both the FDA and the pharmaceutical company for such exceptions.
Data
the quantitative expression of the dependent variable
Nominal data
there is no inherent value in the number, it is simply associated with a group or outcome (i.e. in name only; eg., male or female, blood type)
Ordinal data
there is a sense of a higher number reflecting something greater, but the difference from 1 to 2, may not be the same as from 3-4. If the scale is large enough, the discreetness of the differences become less different and begin to behave as continuous
Continuous data
Clearly, the most informative since the intensity or measure increases in a linear fashion indicative of the magnitude of the difference.
Observer bias (variability)
The person rating the subject has some preconceived notion of what should happen or is skewing data because of some type of interpretation
Instrument bias
The instrument used to measure something is not calibrated correctly
Population
All possible members of a group under study
Sample
Is a portion of a population chosen to reflect characteristics of it.
Sampling error
A sample that is not representative of a population
Convenience sample
occurs when one selects those elements of the population that are most accessible.
Judgment sample
occurs when subjects that form a sample are chosen by an individual familiar with the characteristics of the population
Random sample
Each subject in the population has an equivalent chance or probability of being included in the sample.
simple random sample
Equal chance for all – generally generated from a computer list or drawing subjects like the lottery.
systematic random sample
Is created by selecting one subject randomly and then choosing the other subjects at evenly spaced intervals until the desired sample size is obtained.
Stratified Sample
Generated by grouping subjects into some type of inherent logical characteristic.
Cluster Sample
A variation on a stratified sample although the characteristics may not necessarily be so obvious and could simply be arbitrary. Subjects are chosen because they fall into a cluster of some sort and then you measure the response from every member in the cluster.
Purposeful Sampling
Occurs when subjects or cases are chosen because they exhibit particularly rich characteristics that will help in identifying results.
Snowball or chain sampling
identifies cases of interest from people who know people who know what cases are information-rich, that is good examples for study, good interview subjects
Criterion sampling
You set a criteria and pic all cases tht meet that criteria, for example, all ladies six feet tall, all white cars, all farmers that have planted onions.
Theory
The conceptual structure used to explain existing facts and predict new ones.
