Exam 3

Question 1

Why use Analysis of Variance? (ANOVA)

Answer 1

Compares more than two groups: Designed for multi-level or multifactor designs

Similar comparison of within group and between group variability

Can be applied to independent groups or repeated measures

F Statistic is the key result; ANOVA yields a number; go to the F table and find the critical value; if the statistic ran is greater than the critical value, there is a positive change; a negative number is a negative change

Question 2

Describe the characteristics of the One-way ANOVA for independent Measures

Answer 2

For comparison of 3 or more levels of the independent variable; groups do not have a relationship

• Null hypothesis is that all 3 or more means are not different
• Experimental (Alternative) hypothesis is that at least two are different

Comparison of individual scores for each subject in the group compared to the mean of the group

Comparison of individual scores to group mean

Difference of individual scores from group mean squared and summed – sum of squares

Larger the sum of squares the greater the variability within the group

Partitioning of sum of squares -Between-group sum of squares – intervention effect + error -Within-group sum of squares – error Degrees of Freedom -n-1 -Between groups - # groups-1 -Within groups - total # of subjects in all groups -1 Mean Square - Divide sum of squares by degrees of freedom (df) F-value – divide between groups by within group mean square values

Question 3

Describe the factors (variables) of the ANOVA table for One-way ANOVA for independent Measures

Answer 3

Sigificance level – p-value found from a table of F-value at appropriate df (n -1; number of independent variables minus one) Add Photo

Question 4

Describe the characteristics of the Two-way ANOVA for independent Measures

Answer 4

Compare multiple factors or interventions

Main effects: -What is the effect of one factor, independent of the other factor

-Interaction effect: What is the effect of interaction between the two factors?

Basically two groups; asks the question, did the intervention help or not?

Question 5

Describe the factors (variables) of the ANOVA table for Two-way ANOVA for independent Measures

Answer 5

Study -3 types of muscle stretching (df=2) at 2 joint positions (df=1) on joint range of motion (ROM) in 55 subjects

• Sum of squares (SS), Mean square (MS) calculated as before for stretch, position & interaction between stretch & position
• F value for stretch, position & interaction between stretch & position by dividing MS by within group MS (error)
• Significant difference between different stretching techniques (p < 0.001) but not between different positions ( p = 0.694)
• Significant interaction between different stretching techniques and joint positions (p < 0.001) so the effect of stretching depended upon the joint position
• So although position did not have a main effect on it own, position could influence the main effect of stretching

Question 6

Describe the factors (variables) of the ANOVA for Repeated Measures for Mixed Designs

Answer 6

Study RCT with effect of 6 weeks of stretching on ROM

• Two stretching groups and control (df=2)
• Pre-post repeated measures (df=1)
• Significant difference between groups (p=0.0012) and pre-post (p=0.0001)
• And significant interaction between groups & time (p=0.0111)
• Pre/Post difference depended upon which group subjects were in

Question 7

What is the purpose for individual pairwise comparisons and what used to make them?

Answer 7

Now that a significant difference has been determined – can do individual pair-wise (same as paired or matched) comparisons

Can use individual T-tests (paired or unpaired where appropriate) to compare individual comparisons to determine where the differences seen in the ANOVA are

Question 8

What is the Analysis of co-variance (ANCOVA) used for?

Answer 8

• a general linear model which blends ANOVA and regression.

ANCOVA evaluates whether population means of a dependent variable (DV) are equal across levels of a categorical independent variable (IV) often called a treatment, while statistically controlling for the effects of other continuous variables that are not of primary interest, known as covariates (CV) or nuisance variables.

Question 9

What is the multivariate analysis of variance (MANOVA) used for?

Answer 9

Step above ANOVA

is a statistical test procedure for comparing multivariate (population) means of several groups. As a multivariate procedure, it is used when there are two or more dependent variables, although statistical reports provide individual p-values for each dependent variable in order to test for statistical significance.

It helps to answer:

• Do changes in the independent variable(s) have significant effects on the dependent variables?
• What are the relationships between the dependent variables?
• What are the relationships between the independent variables?

Question 10

What is the rationale for using parametric and non-parametric statistics?

Answer 10

• When data not normally distributed (there is not a homogeneity of variance within or between groups)
• Small sample sizes where the sample’s distribution may not reflect that of the population
• Use of nominal and ordinal level data which are likely not to be normally distributed

Question 11

What are the parametric statistics?

Answer 11

Two Independent Groups:

• Unpaired t-test/Mann-Whitney U test

Two Related Scores (Same Individual):

• Paired t-test/Wilcoxon Signed-Ranks test

3+ Independent groups:

• 1-Way ANOVA/Kruskal-Wallis ANOVA by Ranks

3+ Related Scores:

• 1-Way Repeated Measures ANOVA/Friedman 2-Way ANOVA

Question 12

What is correlation?

Answer 12

• Correlations can determine relationship but not cause and effect
• Often correlations have a restricted range of values – out of that range correlations vary
• Previously looked at tests of group difference – asking the question is group A different from group B?

•Correlation tests ask
–Is there a relationship between two variables?
–What is the degree & direction of this relationship?
–Is the relationship significant or due to chance alone?

Question 13

What are correlation coefficients and how do you interpret the results?

Answer 13

•Correlation coefficients denoted by “r” give the degree & direction of the relationship

–r = 0 is no relationship
–r = 1 is perfect direct relationship
–r = -1 is perfect inverse relationship

Question 14

What tests are used for different forms of data?

Answer 14

•Pearson Product Moment
–Correlation based upon covariance – large values of one group associated with large values of other & visa versa
–Used with metric level data – those that meeting parametric testing standards

•Spearman Rank Correlation
–Used with ordinal level data

•With dichotomous relationships – Phi coefficient & biserial point correlation

Question 15

Effect Size Calculation

Answer 15

The true magnitude of the effect of an intervention is related: -Not only to the change in means -But also related to the variability of the groups around those means

Statistical significance only looks at the probability that two groups are different, not how much difference exists. (This is the difference between statistical significance and clinical significance)

Effect size was developed to assess the magnitude of differences between groups; Mean difference & SD can be used only if there is a normal distribution

Cohen defined effect size (d) as the difference between the means variability of the groups around the mean, M1 - M2, divided by the standard deviation (SD) of either group

**Effect sizes are generally defined as: -Small (d ≤ 0.2) -Medium (d = 0.2-0.8) -Large (d ≥ 0.8)* **

Effect sizes also represent: -Relative overlap between distributions -Relative percentile of the mean of one group compared to the distribution of the other group

Question 16

Relative Risk

Answer 16

Relative risk (RR) is the risk of an event (or of developing a disease) relative to exposure

Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group

• If relative risk =1, the risk of event under study is equal to the comparison event
• If relative risk >1, the risk of the event is more likely
• An odds ratio < 1 indicates that the condition or event is less likely to occur in the first group

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Question 17

Odds Ratio

Answer 17

Definition - Ratio of the odds of an event occurring in one group to the odds of it occurring in another group

The odds of an event occurring is the ratio of the probability of its occurrence (p) divided by the probability of non-occurrence (1-p)

• If an odds ratio =1, the condition or event under study is equally likely to occur in both groups
• If an odds ratio >1, the condition or event is more likely to occur in the first group
• An odds ratio < 1 indicates that the condition or event is less likely to occur in the first group

To have significantly higher or lower odds of something occurring, the 95% confidence interval cannot overlap 1

Question 18

What are the 5 traditions of qualitative inquiry?

Answer 18

Phenomenological studies

Grounded Theory

Ethnography

Case Studies
Biography

Question 19

What are the purpose(s) of biography?

Answer 19

–Study of an individual and his/her experiences

–“Studied use and collection of the life documents that describe turning-point moments in an individual’s life”

–Interpretative biography – done from a particular perspective

Question 20

What are the different forms of biography?

Answer 20

–Biographical study – life story written by someone else

–Autobiography – life story written by themselves

–Life History –individual’s life & how it reflect cultural themes of society, personal themes, institutional themes told by the individual but supported by other evidence

–Oral History – telling events through personal recollections supported by documents

Question 21

What are the procedural steps in biography?

Answer 21

–Begin – objective facts of life – noting chronologic, course of life path

–Next – gathering stories which expand upon the basic facts

–Organizing around themes or pivotal events

–Exploration of further meaning form stories in context of the organizational principle

–Explain historical context, social events, ideologies, cultural issues and placing life stories into these contexts
–Example - James Madison by Richard Brookhiser begins in 1814 during the War 1812 with the attack on Washington. DC by British to illustrate characteristics of Madison that he then ties back through other phases of Madison’s life

Question 22

What are the challenges of doing a biographical study?

Answer 22

–Need to collect extensive information about subject

–Must have clear understanding of the context to position subject correctly in larger milieu

–Get the right slant to develop a multilayered life

–Bring personal perspective into the story but clearly define & acknowledge those personal viewpoints

Question 23

What are the approaches to a biography?

Answer 23

–Objective – little interpretation

–Scholarly – interpretative within larger context of history

–Artistic – tell good story & may include fictionalized accounts of scenes to illustrate life & may be a fictionalized biography – based upon the life of Michelangelo (“Agony & the Ecstacy” by Irwin Stone)

–Classical VS interpretative
•Classical review materials, develop hypotheses from the perspective of the author
•Interpretive – using materials creatively including transforming writings into thoughts/conversations expanding upon the personal insights of the author – great deal of latitude

Question 24

What are the purpose(s) of a phenomenological study?

Answer 24

–Describe the meaning of the “lived experience” from several individuals standpoint about the concept of phenomenon being described

–Search for the essential, invariant structure or essence or central underlying meaning

–Taking basic statements and reducing them to themes

Question 25

What are the 4 principles that link subject and object in phenomenological studies?

Answer 25

Intentionality of Consciousness * Reality of the object is related to one’s consciousness of it * No separation of subject and object but * Exploring the nature of the object from the perspective of the viewer * Reality of the object stems solely from the experience of that object by the individuals’ perceptions – REALITY IS WHAT IS EXPERIENCED - Suspension of all preconceived notions about what is real - Expression of findings as conceptual not empirical (perception not evidence)

Question 26

What are the procedural steps in a phenomenological study?

Answer 26

Research must understand the philosophical perspectives behind the approach – particularly how people experience the object removing all preconceptions Investigator writes the research question to frame the way she/he will explore the meaning of the phenomenon through the lived experiences of the participants –Data collected through prolonged interview and self reflection with a small number of informants (5-25) –Data is divided into related statements –Clusters of meaning are then derived from these statements to derive what was experienced (textural description) and how it was experienced (structural description) –Write up this analysis so the reader can understand the essential, invariant structure or meaning of the experience

Question 27

What are the challenges of doing a phenomenological study?

Answer 27

–Researcher must be solidly grounded in principles of phenomenological research –Finding participants who have experienced the phenomenon –Bracketing out personal experiences about the phenomenon under study –Research must decide how her/his experiences may have entered in the analysis and explain that interference

Question 28

What are the purpose(s) of a grounded theory study?

Answer 28

–Phenomenonology explores meaning of experience to participants –Grounded theory attempts to generate an abstract analytical schema about how individual will react , interact or take action based upon the phenomenon being studied –Statement of plausible relationship among concepts or between concepts in the form of a narrative statement, visual picture or series of hypotheses/propositions

Question 29

What is the basic methodological approach to grounded theory studies?

Answer 29

–20-30 interviews based upon several visits to the field and saturate (collect data until no more can be found) the categories (events, occurrences) –Begin analysis as data is being collected in “zig-zag” pattern between collecting and analyzing data in a constant comparative manner –Participants are selected to optimize the data collection process

Question 30

What are the procedural steps of data analysis in grounded theory studies including the different types of coding?

Answer 30

Open Coding * Forms initial categories as data is being collected and segmenting information * Within each category – properties or subcategories are ID & used to dimensionalize or show a continuum of properties Axial Coding * New ways of assembly of information after open coding * Uses coding or logic diagram to identify the entire phenomenon * Explores causal conditions – categories of conditions that influence the phenomenon under investigation * Explores strategies or actions/interactions that result from the central phenomenon * Intervening conditions - the narrow and broad conditions that influence the strategies * Delineates consequences – outcomes of the strategies Selective Coding * Integrates the categories along a “story line” developed from the data analysis * At this point conditional hypotheses – propositions – are presented Conditional Matrix * Elucidates, visually portrays other factors that may be influencing the central phenomenon * This may not be part of traditional grounded theory Result is the substantive-level theory which the researchers which can be later empirically tested (This will be verbatim on exam!)

Question 31

What are the challenges of doing a grounded theory study?

Answer 31

–Investigator needs to set aside theoretical ideas or notions so that the analytic, substantive theory can emerge from the data –This is a systematic evolving process with specific steps in data analysis –Must determine when categories are saturated to provide the theory with sufficient data –Needs to recognize that the primary outcome is a theory with its specific components, central phenomenon, causal conditions, strategies, context and consequences

Question 32

What is ethnography?\*

Answer 32

Description and interpretation of a cultural or social group or system

Question 33

What characteristics of a culture are explored in ethnography?\*

Answer 33

Cultural Characteristics Explored in Ethnography * What people do – behaviors * What people say – language * What they make – artifacts * What the structure is – kinship, hierarchy * Function – interactions between group members

Question 34

What are the issues that arise in ethnographic fieldwork?

Answer 34

–Gatekeepers – those that allow entry into the cultural group –Key informants – know key information about the culture –Reciprocity between investigator & subjects –Reactivity – impact researcher has on observed group –Deception – problem for ethical behavior –Description, analysis, interpretation of culture sharing group –Final product holistic cultural portrait that incorporates views of members of the group (emic) and researchers perceptions based on social science perspective (etic)

Question 35

What are the challenges of ethnography?

Answer 35

–Researcher need grounding in cultural anthropology and the meaning of social-cultural systems & concepts used by ethnographers –Need extensive time to collect data including prolonged time in the field –Narratives are written in a literary narrative approach which may be challenge for those involved in behavioral & science research –Possibility the researcher will “go native” & compromise the results – this is a complex set of issues related to immersive field work

Question 36

What are the purpose(s) of a doing a case study?

Answer 36

–Exploration of a bounded system – bounded by time and place – of a program, an event, an activity or individuals –Multiple sources of information used including observation, interviews, AV recording, documents & reports Contextualizing the case requires that it be situated within its setting, physical, social, historical and/or economic –Focus on a case that because of it uniqueness requires study (intrinsic case study) or it may be an issue or issues with the case used as an instrument to illustrate the issue (instrumental case study) –When more than one is done it is a collective case study

Question 37

What are the methodological issues in doing case studies?

Answer 37

–Purposive sampling – selection of sources of information because they are ideal in understanding the case –Multiple sources of information used including observation, interviews, AV recording, documents & reports –Holistic analysis of entire case or embedded analysis of just a feature –Detailed description with emergence of theses or assertions –Analysis is rich within the context of the case to develop themes within the case (within-case analysis) or across different cases (cross-case analysis)

Question 38

What are the challenges of doing a case study?

Answer 38

–Must clearly ID the case and how it is bounded recognizing that there may be several alternatives that might be selected from –Decide on a single cases or multiple cases and if multiple – how many to get the depth needed to gain understanding –Have a rationale for selecting a particular case and gathering info on the case –Planning the data collection to have enough info to completely describe in-depth the case –Deciding on the boundaries – not too narrow to limit conclusions and generalizability and not too broad to be there forever collecting date – need clean beginning and end points