Nursing Research Exam 2

quantitative research

method of collecting information that is quantifiable

variables

a factor that can be changed or controlled in an experiment

Dependent Variable (DV)

a variable which is hypothesized to depend on or be caused by another variable

Independent Variable (IV)

variable that is believed to be the cause or influence of another variable

extraneous variable (mediating variable)

variable occurs between the IV & DV and interferes with interpretation of DV

design

- plant or blueprint to conduct a study

- systemic process to test research questions and hypotheses

- structure of maintaining control in a study

control

ruling out extraneous or mediating variables the compete with the IV as an explanation for a study's outcome (DV)

Randominzation

a process of choosing the members of the experimental and control groups without bias

homogeneity

the quality of being similar or comparable in kind or nature

heterogeneity

state of being dissimilar, composition from unlike elements

statistical control

adjusting for the effects of confounded variables by statistically adjusting the value of the dependent variable for each treatment condition

experimental design

the process of carrying out research in an objective and controlled fashion so that precision is maximized and specific conclusions can be drawn regarding a hypothesis statement

experimental design is what kind of assignment

random assignment

experimental group

-> pretest -> rx -> posttest

control group

-> pretest -> posttest

experimental issues to consider

- pilot studies (aka feasible study)

- Hawthorne effect -> blinding

- contamination of treatment

- lab vs. field experiment

- RCT

feasible study

a preliminary exploration of a proposed project or undertaking to determine its merits and viability.

Hawthorne effect

A change in a subject's behavior caused simply by the awareness of being studied

blinding

the concealment of group allocation from one or more individuals involved in a clinical research study

experimental design advantages

- most powerful design

- most confidence in causation

experimental design disadvantages

- variables must be able to be manipulated

- may be difficult to apply and extend in the "real world"

quas-experimental design

involves manipulation of the independent variable (IV) and decreases confidence in causation

quasi-experimental design lacks either:

- randomization to groups

- control group

non-equivalent control group design

A quasi-experimental design in which non-equivalent groups of participants participate in the different experimental groups, and there is no pretest.

After-Only Non-Equivalent Control Group Design

participants in one group are exposed to a treatment, a nonequivalent group is not exposed to the treatment, and then the two groups are compared. (no pretest)

time series design

a research design where patterns of scores over time are compared from before a treatment is implemented and after a treatment is implemented

advantages of quasi-experimental designs

- more practical, feasible, and generalizable

- more adaptable to "real world" applications

disadvantages of quasi-experimental designs

less confidence in cause-and-effect conclusions

extraneous variables (mediating variable)

variable occurs between the IV & DV and interferes with interpretation of DV

manipulation

something that is done to some subjects of an experiment but not others so that the outcomes of the two groups can be compared

Validity

- results of the study are valid

- faithfulness that the researcher measured what he/she wanted to study- with precision

internal validity

- degree to which it can be interred that the experimental treatment, rather than the control group, resulted in the observed effect

- degree to which the researcher eliminated bias

-- ruling out other factors or threats as rival explanations of the relationship between the variables

threats to internal validity

History

Maturation

Testing

Instrumentation

Diffusion of treatment

Regression towards the mean

Selection bias

Attrition

history

- refers to events outside of the experimental setting that may affect the DV (outcome)

- specific events which occur between the first and second measurement

maturation

- the developmental, biological or psychological processes within the individual which act as a function of the passage of time

- this is a threat that is internal to the individual participant

testing

- taking the same test repeatedly could influence the subject's responses the next time the test is taken

- frequently familiarity with a test or scale could affect performance or results because past responses were remembered

instrumentation

- changes in the measurement of the variables or observational techniques that may account for changes in the obtained measurement

- can occur between the pre-test and post-test

mortality

- loss of study subjects from the first-data-collection point (pretest) to the second data collection point (post-test)

- the differences between the pre-test and post-test may be because of the drop-out rate of subjects from a specific experimental group, which would cause the groups to be unequal

selection bias

- when bias is introduced because of the selection of subjects

- the sample obtained is not representative of the population intended to be analyzed

external validity

- refers to the extent to which the results of an experiment can be generalized across populations, time and settings

threats to external validity

selection effects, reactive effects, measurement effects

selection effects

- occurs when the researcher cannot attain the ideal sample

- proper randomization is not acheived

- should be noted in the limitation sections of the article

reactive effects

- also known as the Hawthorne effect

- a type of reactivity in which individuals modify an aspect of their behavior in response to their awareness of being observed

measurement effects

administration of a pre-test in a study can affect the generalizability of the findings

non-experimental quantitative designs

- descriptive

- correlational

- longitudinal

non-experimental quantitative designs key characteristics

- indenpendent variable non-manipulable

- cannot establish causation

descriptive studies

- accurate information about subjects

- provides background/preliminary evidence for other studies

- economical and accurate

- may be superficial

correlational studies

- seek to establish relationships between or among variables

- correlation does NOT establish causation

longitudinal studies

- collect data from the same group at different points in time

- costly

advantages of non-experimental design

- efficient/effective

- large amounts of data

disadvantages of non-experimental design

unable to conclusively demonstrate causal relationship

sampling

The process of selecting representative portion of the designated population for study

Inclusion

the action or state of including or of being included within a group or structure.

exclusion

the process or state of excluding or being excluded.

probability sampling

RANDOM

- equal chance of being selected

-- most rigorous

-- more representative

-- more generalizable

-- low selection bias

non-probability

NON RANDOM

- unequal chance of selection

-- less generalizable

-- less representative

-- high selection bias

simple random sample

- participants have an equal chance of being selected

- Methods

-- draw names from hat

-- table of random numbers

-- computer generated

simple random sampling advantages

- sample selection is not subject to conscious biases

- representativeness of the sample

stratified random sample

- population divided into homogenous strata or subgroups

- stratified based on characteristics that represent the population

--age

--gender

--ethnicity

stratified random sampling advantages

- maximizes representativeness

- can make comparison among subsets

- able to oversample a disproportionately small stratum to adjust for underrepresentation

multi-stage cluster sampling

drawing a sample from a population using smaller and smaller groups at each stage

multi-stage cluster sampling advantages

more economical in time and money, especially if population is large and geographically dispersed.

probability sampling

A type of sampling in which every element in the population being studied has a known chance of being selected for study

probability sampling advantages

- sample selection is not subject to conscious biases

- representativeness of the sample

convenience

selected because of availability

quota

set quota and keep recruiting until you have desired number

purposive

conscious selection of subject you want

network (aka snowballing)

subjects asked to refer others

4 types of non-probability sampling methods

1. convenience

2. quota

3. purposive

4. network

general rule for sample size

larger= more repensentativeness

power analysis

a statistical method to determine the acceptable sample size that will best detect the true effect of the independent variable

objective

free from the researchers personal biases, beliefs, values, attitudes

systemic

data collected in a uniform, consistent, or standard way

observational methods

- observe how people behave under certain circumstances

- structured or unstructured

structured observational method

- specify in advance what behaviors are to be observed

- standardized forms are used for record keeping

- rely heavily on the formal training and standardization of the observers

unstructured observational methods

-Usually involve collecting descriptive information

-Participant observation uses field notes to record the activities, as well as the observer's interpretations

-Anecdotes usually focus on the behaviors of interest and illustrate a particular point

self-report methods

- to collect information about experiences, behaviors, feelings or attitudes

- collecting data on variables that cannot be directly observed or measured

-- quality of life, satisfaction with nursing care, social support, uncertainty and functional status

semantic differential

place mark to indicate your opinion of nursing research

visual analog

when a child points to where her pain falls on a scale she is using which pain rating scale?

physiological measures

- requires the use of specialized equipment

- determine the physical and biological status of subjects

reliability measures...

a measure of the consistency of test or research results

validity measures...

accuracy

error variance

Variability attributable to error

measurement eror

- difference between what really exists and what is measured

- errors

-- chance or random

-- systemic

- reliability concerned with random error

- validity concerned with systematic error

Reliability

- the extent to which the instrument yields the same results repeatedly

- stability

- internal consistency or homogeneity

- equivalence

interrater reliability

- Kappa expresses the level of agreement observed

- K ranges from +1 to 0

- K of 0.80 or better indicates good interrater reliability

content validity

the extent to which a test samples the behavior that is of interest

criterion-related validity

degree to which the observed score and the true score are related

construct validity

- extent that a test measures a theoretical construct, attribute, or a trait

-- hypothesis testing approach

-- convergent and divergent approaches

-- factor analytical approach

nominal

categorical (gender, race)

ordinal

rank, order- distance between categories is unknown

interval/rato

distance between categories is some accepted unit of measurement

mean

average

median

Middle number

mode

the most frequently occurring score(s) in a distribution

predictor variable

the dependent variable in a correlational study that is used to predict the score on another variable

univariate analysis

analysis of a single variable

multivariate analysis

the analysis of the simultaneous relationships among several variables

range

the difference between the highest and lowest scores in a distribution

standard deviation

a measure of variability that describes an average distance of every score from the mean