Laissez les bon temps roulez!! The Logistics of Constructing a Research Purpose Statement, Questions and Hypotheses, Design, Sample, Measurement, and Data Analyses Plan Christopher J. Burant, PhD, Assistant Professor, School of Nursing Case Western Reserve University Cleveland, OH Co-Director of the GRECC Methodology Center, the Louis Stokes Cleveland Veterans Administration Medical Center What will we learn today? How to build models to guide your research. How to construct a Research purpose statement, question, and hypotheses. How to choose the appropriate data analysis for your research purpose, question, or hypotheses. Nuts and Bolts on Design and Sampling Models can be used to help develop Research Hypotheses, Questions and Purpose Statements MODEL DEVELOPMENT IDEA CONCEPTS THEORY/MODEL MEASURES PURPOSE DESIGN Building a Model • Based on LTE – Logic – Theory – Prior Emperical Evidence • Build models based on previous models • Construct own models – Causal Ordering – Hypotheses Driven Using Previous Models Race/Ethnicity Socioeconomic Status Gender EXPLANATORY VARIABLES Social, Political, and Economic Conditions and Policy Medical Care and Insurance Health Outcomes 1. Mortality 2. Institutionalization 3. Morbidity (Chronic) 4. Functional Limitations 5. Self-Rated Health 6. Cognitive Function 7. Depression Psychosocial Risk Factors 1. Health Behaviors 2. Social Relationships and Supports 3. Chronic and Acute Stress 4. Psychological Dispositions 5. Social Roles and Productive Activities Physical/Chemical and Social Environmental Hazards 8 SES Education Occupation Income Subjective SES SES Inequality Environmental Resources & Constraints Neighborhood Factors Social Capital Work Situation Family Environment Social Support Discrimination Race Gender Psychological Influences Resilience/Reserve Capacity Negative Affect (anxiety, depression, hostility) Negative Expectations Perceived Discriminations Reactive Responding Access to Medical Care Exposure to Carcinogens & Pathogens Health Outcomes Health Cognitive Function Physical Function Disease Health-Related Behaviors Disease Trajectories Recovery Relapse Secondary Events Central Nervous System & Endocrine Response Mortality Life Course 9 SES Neighborhood or Community Hazards and Supports Social Conditions (e.g., Discrimination) That Are Correlated With SES Other Aspects of SES That Affect Health (e.g., Access to Medical Care, Nutrition, Role Models) STRESS Behaviors That Impair or Support Good Health -Tobacco Use - Exercise Biological Changes in Systems -Immune System - Endocrine System Changes in Illness-Related Behavior -Prevention - Early detection Health Outcomes 10 Period, Cohort, and Geography Class, Race, and Gender School and Peers Workplace and Peers Family of Destination’s Social Capital Family of Origin’s Social Capital Child’s Social Capital Child’s Health Capital Adult’s Social Capital Adult’s Health Capital 11 Negative Parental or Peer Role Models Poor Childhood Health Habits Poor Adult Health Habits Poor Adult Health Poor Childhood Socioeconomic Environment Inhibits Development of Self-Esteem and Skills Poor School Performance Poor Adult Environment Teenage Parenthood 12 Occupation Education Income Parental Socioeconomic Position Health Assets/Wealth Race/Ethnicity Sex/Gender Age 13 Introduction • Models should be developed based on Logic, • • • Theory and prior Empirical Evidence (LTE) Variables chosen for the model should be based on LTE. When choosing predictors for a model, variables that should be included should be the same ones chosen for a regression, such as sociodemographics, clinical, and psychosocial relevant variables. One should also take into account adding all appropriate confounders to the model. Causation “Principle by which cause and effect are established between two variables. It requires that there be a sufficient degree of association (correlation) between the two variables, that one variable occurs before the other, (that one variable is clearly the outcome of the other), and that there be no other reasonable causes for the outcome. Although in its strictest terms causation is rarely found, in practice strong theoretical support can make empirical estimation of causation possible.” (p. 579) - Hair, Anderson, Tatham, & Black (1998) AGE ETHNICITY EDUCATION INCOME QUALITY OF LIFE RELIGIOSITY WOMAC CHARLSON DEPRESSION Regression representing the predictors of Quality of Life. AGE ETHNICITY EDUCATION INCOME QUALITY OF LIFE RELIGIOSITY WOMAC CHARLSON DEPRESSION AGE ETHNICITY EDUCATION INCOME QUALITY OF LIFE RELIGIOSITY WOMAC CHARLSON DEPRESSION AGE ETHNICITY EDUCATION INCOME QUALITY OF LIFE RELIGIOSITY WOMAC CHARLSON DEPRESSION AGE ETHNICITY EDUCATION INCOME QUALITY OF LIFE RELIGIOSITY WOMAC CHARLSON DEPRESSION AGE ETHNICITY EDUCATION INCOME RELIGIOSITY QUALITY OF LIFE WOMAC CHARLSON DEPRESSION AGE ETHNICITY RELIGIOSITY WOMAC EDUCATION INCOME QUALITY OF LIFE CHARLSON DEPRESSION AGE ETHNICITY EDUCATION RELIGIOSITY WOMAC CHARLSON INCOME QUALITY OF LIFE DEPRESSION AGE ETHNICITY EDUCATION INCOME RELIGIOSITY WOMAC CHARLSON DEPRESSION QUALITY OF LIFE AGE ETHNICITY EDUCATION INCOME RELIGIOSITY WOMAC CHARLSON DEPRESSION QUALITY OF LIFE SETTING UP THE MODEL • Models should be developed based on Logic, Theory or prior Empirical evidence. • Variables should be temporally ordered with the most antecedent in time on the left hand side of the model. • Create hypotheses based on the bivariate relationships of the variables in the model a priori to any analyses. • Run correlations on all variables. Draw in paths of all significant relationships. This will be the initial model. AGE ETHNICITY EDUCATION INCOME RELIGIOSITY WOMAC CHARLSON DEPRESSION QUALITY OF LIFE RELIGIOSITY ETHNICITY EDUCATION INCOME WOMAC CHARLSON DEPRESSION AGE QUALITY OF LIFE RELIGIOSITY WOMAC EDUCATION INCOME CHARLSON DEPRESSION AGE QUALITY OF LIFE ETHNICITY INCOME RELIGIOSITY WOMAC CHARLSON DEPRESSION AGE EDUCATION ETHNICITY QUALITY OF LIFE RELIGIOSITY WOMAC CHARLSON DEPRESSION AGE QUALITY OF LIFE EDUCATION INCOME ETHNICITY WOMAC CHARLSON DEPRESSION AGE QUALITY OF LIFE EDUCATION INCOME ETHNICITY RELIGIOSITY WOMAC DEPRESSION AGE QUALITY OF LIFE EDUCATION INCOME ETHNICITY CHARLSON RELIGIOSITY DEPRESSION WOMAC AGE QUALITY OF LIFE EDUCATION INCOME ETHNICITY CHARLSON RELIGIOSITY WOMAC AGE QUALITY OF LIFE EDUCATION DEPRESSION INCOME ETHNICITY CHARLSON RELIGIOSITY AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON SOCIODEMOGRAPHIC FACTORS PHYSICAL/PSYCHOLOGICAL FACTORS AGE WOMAC EDUCATION QUALITY OF LIFE INCOME DEPRESSION ETHNICITY RELIGIOSITY CHARLSON Writing Research Purpose Statements, Questions, and Hypotheses and Planning your Analyses Spell it ALL out… Step by step: 1. 2. 3. WHAT are your research purpose statements, questions, or hypotheses? HOW will the variables be operationalized? What is YOUR analysis plan? Writing Research Purpose Statements, Questions, and Hypotheses and Planning your Analyses Spell it ALL out… Step by step: 1. 2. 3. WHAT are your research purpose statements, questions, or hypotheses? HOW will the variables be operationalized? What is YOUR analysis plan? Where to start? HERE!!! What do I use a Hypotheses, a Research Question, or Research Purpose Statements? It really doesn’t matter. These are very similar. However, there are subtle differences. It is really the choice of the investigator or your dissertation advisor. Hypotheses vs. Research Questions and Research Purpose Statements What is a Hypothesis? Remember back in grade school when Sister Alberta Einstein told you it was an “educated guess”. Well that is what it is an “educated guess”. It is created based on Logic, Theory, or Prior Empirical Evidence (LTE). It is more specific than Research Questions or Research Purpose Statements. What are Hypotheses? It is more specific than Research Questions or Research Purpose Statements. It includes a direction. (Hey what do you mean direction?) To have a quantifying statement such as: “higher or lower”, “more or less”, “larger or smaller”, “positive or negative relationship” This will also allow for a one-tailed statistical significance test. An Example of a Hypothesis? It is hypothesized that in older hospital patients, those with higher levels of optimism will have lower levels of depressive symptoms. Another way to state this is: It is hypothesized that in older hospital patients, optimism will be negatively related to depressive symptoms. Tips for Writing Hypotheses If you have 2 variables state whether it is a relationship, a comparison, or predictive in nature. State the Independent Predictor Variable and Dependent Outcome Variable in that order State direction in describing variables (e.g. “more” “less”) Tips for Writing Hypotheses Name Populations Be Specific Use plural forms to represent groups Do not use two different terms to refer to the same variable within a single hypothesis or across several hypotheses. Single sentence can have multiple hypotheses. For multiple related hypotheses use a numbered list (bullet points). What are Research Questions and Research Purpose Statement? Why are they lumped together? They are conceptually identical. They are just stated differently. They are more general in nature. What are Research Questions and Research Purpose Statement? Often used in exploratory, pilot studies (“sailing unchartered waters”), when trying to identify relationship or comparisons. They are non-directional. They do not have quantifying statements. Used for a two-tailed statistical significance test. Example of a Research Questions and a Research Purpose Statement? Research Question: In older hospital patients, how is their level of optimism related to their level of depressive symptoms? Research Purpose statement: The purpose of this research is to identify how levels of optimism are related to levels of depressive symptom in older hospital patients. Tips for writing Research Questions and Research Purpose Statements? Do not state a research questions that have a “yes” or “no” answer In older hospital patients, is their level of optimism related to their level of depressive symptoms? If you have 2 variables state whether it is a relationship, a comparison, or predictive in nature. Tips for writing Research Questions and Research Purpose Statements? State the Independent Predictor Variable and Dependent Outcome Variable in that order Name Populations Use plural forms to represent groups Recommended for no relationships (e.g., for descriptives), qualitative, and new or contradictory (to previous research) topic Tips for writing Research Questions and Research Purpose Statements? Use plural forms to represent groups Do not use two different terms to refer to the same variable within a single Research Question/Purpose or across several Research Question/Purposes. Single sentence can have multiple hypotheses. For multiple related Research Question/Purposes use a numbered list (bullet points). Where to start? HERE!!! What QUESTIONS are you trying to answer? Are you testing: Differences between groups? Relationships between variables? A variable predicting another variable? Changes over time? Univariate descriptives of variables Writing a Methodologically Sound Research Proposal Spell it ALL out… Step by step: 1. 2. 3. WHAT are your research purpose statements, questions, or hypotheses? HOW will the variables be operationalized? What is YOUR analysis plan? Choosing Instrumentation Should I develop a new tool or use an existing tool? Instrument development can be a tedious undertaking; Reliability Issues… Validity Issues… Factor analysis… Benefits of Using Existing Instruments Literature to draw upon Effect size information Readily available reliability/validity information Cronbach’s alpha Details on psychometric properties Still More Benefits! (get the idea? Try and AVOID survey development!) Judgmental Validity Criterion Related Validity Content Validity Face Validity Predictive Concurrent Reliability issues related to Validity Consistency of results Survey Development Focus Groups Content Validity Face Validity Piloting testing EFA CFA Convergent and divergent validity Really hard stuff… Writing Research Purpose Statements, Questions, and Hypotheses and Planning your Analyses Spell it ALL out… Step by step: 1. 2. 3. WHAT are your research purpose statements, questions, or hypotheses? HOW will the variables be operationalized? What is YOUR analysis plan? Thinking through the process… Once you narrow your research hypotheses, questions, or purpose statements choose the proper tool to answer them… Levels of Measurement (remember this stuff????) Broadly speaking, data take 2 forms Categorical Nominal Continuous Ordinal Interval Ratio A new look at the variables… IPV: Independent Predictor Variable Stimuli Cause Treatment DOV: Dependent Outcome Variable Outcome Effect Response Thinking through the process… Once you narrow your research hypotheses, questions, and purpose statements choose the proper tool to answer them… Testing group differences? If your IPVs and DOVs are all CATEGORICAL? Independent Predictor Variable= Gender M/F Dependent Outcome Variable=Depressed? Y/N? [CES-D score <16 and >16] Categorical (dichotomized) Categorical (dichotomized) Chi Square… The Chi Square What is a GOOD Research Question that should be analyzed with a Chi Square ? Among elderly patients, what are the differences by gender in being diagnosed as Depressed? The Chi Square What is a GOOD Research Purpose statement that should be analyzed with a Chi Square ? The purpose of this research is to identify the differences by gender in being diagnosed as Depressed within an elderly patients sample. The Chi Square What is a GOOD Research Hypotheses thath should be analyzed with a Chi Square ? It is hypothesized that among elderly patients females will be more likely to be diagnosed with Depression as compare to males Thinking through the process… What Analysis would you run if your Research Hypotheses, Question or Purpose Statement had the following: Dichotomous Independent Predictor Variable 2 Groups Continuous Dependent Outcome Variable A composite scale score Male/female Intervention/control Depression Scale GPA I am sure you guessed an Independent Samples T-test. The Independent Samples T Test So what would be a GOOD Research Question that should be analyzed with an Independent Samples T Test? Same as the Chi Square question without the cut point! Among elderly patients, what are the differences by gender (IPV=M/F) on their score of depressive symptoms? (DOV= Score on a CES-D {raw score of summed items 0-60…etc.}) The Independent Samples T Test So what would be a GOOD Research Purpose statement that should be analyzed with an Independent Samples T Test? Same as the Chi Square question without the cut point! The purpose of this research is to identify the differences by gender (IPV=M/F) on depressive symptoms within an elderly patients sample? (DOV= Score on a CES-D {raw score of summed items 0-60…etc.}) The Independent Samples T Test So what would be a GOOD Research Hypotheses that should be analyzed with an Independent Samples T Test? Same as the Chi Square question without the cut point! It is hypothesized that among elderly patients, Females will have higher scores of Depressive Symptoms as compared to Males. (DOV= Score on a CES-D {raw score of summed items 0-60…etc.}) Thinking through the process… What Analysis would you run if your Research Hypotheses, Question or Purpose Statement was: Comparing 2 continuous level variables…change over time… A composite score, pre and post intervention A mom’s composite score with her child’s composite score You guessed it a Paired T-Test. The Paired T Test So what would be a GOOD Research Question that should be analyzed with a Paired T-test? Among elderly patients, how do their scores of depressive symptoms change from pre-treatment to post-treatment? The Paired T Test So what would be a GOOD Research Purpose statement that should be analyzed with a Paired T-test? The purpose of this research is to identify among elderly patients the change in their scores of depressive symptoms from pre-treatment to posttreatment. The Paired T Test So what would be a GOOD Research Hypotheses that should be analyzed with a Paired T-test? It is hypothesized that among elderly patients, the change in their scores of depressive symptoms from pre-treatment to post-treatment will decrease. Thinking through the process… What Analysis would you run if your Research Hypotheses, Question or Purpose Statement was: Comparing 3 or more continuous level variables…change over time… A composite score, From Baseline to TIME 2 You are right again a Repeated Measures ANOVA Repeated Measures ANOVA So what would be a GOOD Research Question that should be analyzed with a Repeated Measures ANOVA? Among elderly patients, how do their scores of depressive symptoms change from Admit to Discharge to one month post-hospitalization? (You see 3 time periods) Repeated Measures ANOVA So what would be a GOOD Research Purpose statement that should be analyzed with a Repeated Measures ANOVA? The purpose of this research is to identify among elderly patients the change in their scores of depressive symptoms from Admit to Discharge to one month post-hospitalization? Repeated Measures ANOVA So what would be a GOOD Research Hypotheses that should be analyzed with a Repeated Measures ANOVA? It is hypothesized that among elderly patients, the change in their scores of depressive symptoms from from Admit to Discharge to one month posthospitalization will decrease over time? Thinking through the process… What Analysis would you run if your Research Hypotheses, Question or Purpose Statement had the following: Categorical Independent Predictor Variable 2 or more Groups (preferably 3 or more) Continuous Dependent Outcome Variable A composite scale score IPV=MSN, DNP or PhD? (grouping variable) DOV=Quality of life scale (0-100) Depression Scale You are correct a 1-Way ANOVA 1-Way ANOVA So what would be a GOOD Research Question that should be analyzed with a 1–Way ANOVA? Which group of advanced-degreed nurses score highest on a Quality of Life measure? 1-Way ANOVA So what would be a GOOD Research Purpose Statement that should be analyzed with a 1– Way ANOVA? The purpose of this research is to identify which group of advanced-degreed nurses score highest on a Quality of Life measure? 1-Way ANOVA So what would be a GOOD Research Hypotheses that should be analyzed with a 1–Way ANOVA? It is hypothesized that nurses with a PhD score highest on a Quality of Life measure as compared to nurses with an MSN or a DNP? Thinking through the process… What Analysis would you run if your Research Hypotheses, Question or Purpose Statement had the following: Two continuous variables and you wanted to test the relationship between the two variables. Depressive Symptoms Quality of Life Correct a Correlation Correlation So what would be a GOOD Research Question that should be analyzed with a Pearson r correlation? Among elderly patients, what is the relationship between depression scores and quality of life scores? Each variable is continuous. Correlation So what would be a GOOD Research Question that should be analyzed with a Pearson r correlation? The purpose of the research is to identify the relationship between depression scores and a quality of life scores within a sample of elderly patients? Correlation So what would be a GOOD Research Hypotheses that should be analyzed with a Pearson r correlation? It is hypothesized that among elderly patients, those with higher depression scores will have lower quality of life scores. Thinking through the process… What Analysis would you run if your Research Hypotheses, Question or Purpose Statement had the following: Continuous Independent Predictor Variable Depression Scale Continuous Dependent Outcome Variable Quality of Life Casual order (IPV/DOV) often needs to be determined chronologically. Which happens first? Use terms like: predicts, impacts, affects, causes, contribute to Right again a Regression Regression So what would be a GOOD Research Question that should be analyzed with a Regression? Among elderly patients, do depression scores impact quality of life scores? IPV and DOV variables are continuous. Regression So what would be a GOOD Research Question that should be analyzed with a regression? The purpose of the research is to identify if depression scores impact quality of life scores within a sample of elderly patients? Regression So what would be a GOOD Research Hypotheses that should be analyzed with a regression? It is hypothesized that among elderly patients, higher depression scores will contribute to lower quality of life scores. Thinking through the process… What Analysis would you run if your Research Hypotheses, Question or Purpose Statement was: Describing a variable Continuous (e.g., A1C levels) Categorical (e.g., Political Affiliation) You guessed it univariate descriptive statistics for continuous (e.g., Means, SD, & range) and Categorical (Frequencies and Percentages) Univariate Descriptive Statistics So what would be a GOOD Research Question that should be analyzed with univariate descriptive statistics? Among diabetic patients, what is their mean A1C level? Univariate Descriptive Statistics So what would be a GOOD Research Purpose statement that should be analyzed with univariate descriptive statistics? The purpose of the research is to identify the mean A1C level among diabetic patients. Univariate Descriptive Statistics So what would be a GOOD Research Hypothesis that should be analyzed with univariate descriptive statistics? It is hypothesized that among diabetic patients the mean A1C level is above 7%. Now that you have your research question, purpose statement or hypotheses, you have to decide on your research design. Are you looking for an experimental or a non-experimental design? Experimental – researchers give treatment and observe changes in behaviors. Could be with a control vs. treatment group design R O X O R O O Could be just with a treatment group O X O Are you looking for an experimental or a non-experimental design? Non-Experimental – researchers do not give treatments and describe subjects as they naturally exist without experimental treatments. Causal Comparative Study – target group ( e.g., with an illness) vs. control group (e.g., absent of illness) and match by characteristics Other examples: surveys, case studies, longitudinal, correlational, qualitative, chart reviews Hey Chris, Can you touch base on Sampling You Betcha, I Can Types of Sampling Simple random sampling – every member of population has equal chance of being included in sample. Samples of convenience – Used with hard to get samples, identifying support for new theory. Often used for pilot work Types of Sampling Stratified random sampling – divide sample into strata. Match % of sample with % in population. Reduces sampling bias Cluster Sampling – Draws groups instead of individuals (e.g., Churches, schools) Types of Sampling Purposive sampling – select from individuals whom will be a good sources of information (e.g., caregivers) Snowball Sampling – locate participants who are hard to find from other like subjects. Now you are on the right track! You have your (at least rough) Research Question, Research purpose statement, or Research Hypotheses! Now you are on the right track! You have your (at least rough) Research Question, Research purpose statement, or Research Hypotheses! You have operationalized your variables of interest! Now you are on the right track! You have your (at least rough) Research Question, Research purpose statement, or Research Hypotheses! You have operationalized your variables of interest! You have chosen your statistics to answer them… Now you are on the right track! You have your (at least rough) Research Question, Research purpose statement, or Research Hypotheses! You have operationalized your variables of interest! You have chosen your statistics to answer them… You have learned a little on design and sampling. Now, you have enough information to be dangerous. Resources Worth Owning Patten: Proposing Empirical Research: A guide to the Fundamentals. Patten: Understanding Research Methods. A REALLY nice primer Great overview of Research Methods Pyrczak and Bruce: Writing Empirical Research Reports Very nice companion piece