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MEDT 401 Exam 2

Study guide for exam 2

Concept an abstraction based on observations of certain behaviors or characteristics. For example, stress, pain etc.
Construct an abstraction or concept that is deliberately invented (constructed) by researchers for a scientific purpose. Often used interchangeably with concept however construct is usually a more complex abstract- for example self-care.
Theory Systematic, abstract explanation of some aspect of reality. Building blocks of theory.
Experimental studies The research often starts with a theory or conceptual model and predicts how the phenomena will behave in the real world.
Deductive reasoning Used to describe test or predict the application of a theory to a particular phenomenon.
Inductive reasoning Used in qualitative research to develop theories about phenomenon.
How are boundaries set in experimental research? By sampling identify inclusion and exclusion criteria.
What are the four major categories of quantitative research? Nonexperimental, pre-experimental, quasi-experimental, true experimental
Nonexperimental Studies in which the researcher collects data without introducing any treatment or change.
Pre-experimental Research design that does not include mechanisms to compensate for the absence of either randomization or a control group.
Quasi-experimental A study in which the subjects are not randomly assigned to treatment conditions, but the researcher does manipulate the independent variable and exercises certain controls to enhance the internal validity.
True experimental A study in which the investigator manipulates the independent variable and randomly assigns subjects to different conditions.
What is the purpose of experimental research? describe, explain, predict
What are some of the research designs used for experimental studies? Pretest-post-test, post-test only, Solomon Four Group, Factorial, Repeated Measures
Pretest-post-test Data are collected from research subjects both before and after introduction of the experimental intervention (also referred to as before-after design).
Posttest Only Data is collected from research subjects only after the introduction of the experimental intervention. (also referred to as after-only design).
Solomon Four Group Uses before-after design for one pair of experimental and control groups and after-only for second pair.
Factorial Two or more independent variables are simultaneously manipulated. Allows researcher to perform a separate analysis of the main effects of the independent variables plus interaction effects of those variables.
Repeated Measures one group of subjects is exposed to more than one condition or treatment in random order; also referred to as cross-over design
What are some of the research designs used for quasi-experimental studies? Non-equivalent control group; Time series
Non-equivalent control group Involves a comparison group that was not developed on the basis of random assignment, however pre-intervention data is obtained to assess the initial equivalence of the groups.
Time series Collection of information over an extended period of time, with multiple data collection points both before and after introduction of the treatment.
What are some of the research designs used for nonexperimental studies? Ex Post Facto-correlation; Descriptive
Ex Post Facto-correlation Research is conducted after the variations in the independent variable have occurred in the natural course of events. Causal explanations are inferred after the fact.
Descriptive Accurate portrayal of the characteristics of persons, situations, or groups and/or the frequency with which certain phenomenon occur.
What is purpose of literature review? To determine previous research on the topic. To determine the relationship between current knowledge and identified problem. To provide rationale for a design.
Read literature critically to: Understand level of knowledge of a particular problem area. Identify gaps in knowledge development. Determine next logical research step. Identify potential measures for a particular study. Must set boundaries in literature review
When must research questions be posed in experimental research? Before research begins.
What is a research question called in qualitative research? Query- a broad statement that identifies both a particular phenomenon and a context for a study.
Variable A concept or construct to which numerical values are assigned
Types of variables Dependent, independent, extraneous or confounding variable
Validity The extent to which what is being measured is a reflection of the underlying concept
Internal validity ability of research design to answer accurately the research question
History threat to internal validity effect of external events on study outcomes
Testing threat to internal validity effect of being observed or tested on study outcome
Instrumentation threat to internal validity extent to which the instrument is accurate in its measurement and extent instrument may effect outcome
Maturation threat to internal validity effect of passage of time
Regression threat to internal validity effect of cluster around mean
Mortality threat to internal validity effect on outcome caused by dropping out of study
Interactive threat to internal validity extent to which each of the threats interacts with the others
External Validity Capacity to generalize findings and develop inferences from the sample to the study population
Construct Validity Fit between constructs that are the focus of the study and the way in which the constructs are operationalized
Content Validity Degree to which an indicator seems to agree with a validated instrument measuring the sample construct
Face Validity Extent to which a measuring instrument looks as though it is measuring what it purports to measure.
Reliability Obtaining stable measurement from a single instrument or stability of research design
Measuring reliability: test-retest Same test is given twice to same subject, under same conditions.
Measuring reliability: Split-half technique Instrument items are split in half and correlational procedure is performed between two halves
Measuring reliability: Cronbach’s alpha Statistical procedure used to examine the extent to which all items in the instrument measure the same construct.
What is sampling? The process of selecting a portion of the population to represent the entire population. In experimental studies, sampling is used to set the boundaries of the study.
What is probability sampling? Sampling plans based on probability theory all in population have equal chance of being in sample.
Simple Random sampling Sample frame is created by enumerating all members of a population of interest, and then selecting a sample through completely random procedures such as drawing names from hat or having computer select random numbers
Stratified sampling (population is divided into smaller groups or strata) participants are selected from strata independently
Systematic sampling sampling interval with width (k) is determined based on the needed sample size and every kth element is selected from the sampling frame
Cluster sampling Large groupings (clusters) are selected first (e.g., nursing schools) with successive sub-sampling of smaller units (e.g., nursing students).
What is Nonprobability sampling? Nonrandom methods used. Examples: convenience, purposive, snowball and quota.
Convenience Sample selection of the most readily available persons (or units) as participants in a study; also known as accidental sampling
Purposive Sample researcher selects participants for the study on the basis of personal judgment about which ones will be most representative or production
Snowball Sampling sampling of participants based on referrals from others already in the sample, also known as network sampling
Quota sampling researcher prespecifies characteristics of the sample to increase its representativeness.
What are inferential statistics? Type of statistics used to draw conclusions about population parameters based on findings from a sample.
What is saturation? Point at which an investigator has obtained sufficient information from which to obtain an understanding of the phenomena.
What is crystallization or triangulation? Use of multiple strategies or methods as a means to strengthen the credibility of the researchers’ findings.
What are characteristics of true experimental design? Randomization, manipulation and control
What do the following Campbell and Stanley Symbols mean? R = random sample selection. r = random group assignment. X = independent variable. O = dependent variable.
What is an operational definition? Definition that reduces the abstraction of a concept to a concrete observable form by specifying the exact procedures for measuring or observing the phenomenon.
What is an IRB? Institutional Review Board-group of individuals from an institution who meet to review the ethical considerations of proposed and ongoing studies.
What is informed consent? Ethical principle that requires researchers to obtain the voluntary participation of subjects after informing them of the possible risks and benefits.
What is full disclosure? Adequacy of information provided to research participants necessary for them to make an informed decision about participating in the study.
What are mean, median and mode? Measures of central tendency
What statistical test compares means if you have 2 groups? T-test
What statistical test compares variance when you have two or more groups? Analysis of Variance (ANOVA)
What is effect size? Strength of differences in the sample values that the investigator expects to find.
What is response rate? Rate of participation in a study, calculated by dividing the number of persons participating n the study by the number of persons sampled.
What is the Hawthorne effect or Halo effect? Attention factor-phenomenon in which research subjects may experience change simply from the act of participating in a research project.
What is Pearson's Chi-square? Used to test the hypothesis of no association of columns and rows in tabular data. Probability of <0.05 = justify rejecting null hypothesis. Calculation: (sum of observed - expected count squared)/divided by the expected.
What is Pearson’s correlational coefficient (r2)? A bivariate measure of association (strength) of the relationship between two variables.Varies from 0 (random relationship) to 1 (perfect linear relationship) or -1 (perfect negative linear relationship).
Hypothesis Statement predicting the relationship between variables.
Null Hypothesis States that there is no relationship between variables under study; used primarily in connection with tests of statistical significance as the hypothesis to be rejected.
p value In statistical testing, the probability that the obtained results are due to chance alone; the probability of committing a type I error.
Alpha The probability of a type I error. Represents the researcher’s risk of incorrectly rejecting the null hypothesis (saying there is a difference when in fact there is not). Also referred to as probability p.
Alpha halves The risk of a Type I error when a test of equality is performed. Alpha is divided in half. Two-tailed tests.
Type I Error error created by rejecting the null hypothesis when it is true (the researcher concludes that relationship exists when in fact it does not
Type II Error error created by accepting the null hypothesis when it is false (the researcher concludes that no relationship exists when in fact it does.
Prevalence vs. Incidence Prevalence is the proportion of the population with a given disease at a single point in time whereas incidence is the number of new cases of disease or condition during a specified time frame.
Positive Predictive Value (PPV) the likelihood someone with a positive test result will actually have the disease. It is expressed as a proportion. Percentage of those with a positive test who actually that the disease. a/ a+b
Negative Predictive Value (NPV) likelihood someone with a negative test result will actually not have the disease. Expressed as a proportion it is the percentage of those with a negative test who actually do not have the disease. d/c+d
Sensitivity ability of the test to be positive given the person tested has the disease/problem Expressed as a proportion. It is the percentage of those who are known to have the disease/problem who test positive. Proportion of true positives a/a+c
Specificity ability of the test to be negative given the person does not have the disease/problem. Expressed as a proportion. It is the percentage of those who are known not to have the disease or problem who test negative. The proportion of true negative d/(d+b)
Created by: 100002485764648
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