Podcast
Questions and Answers
What is the primary goal of designing a research study?
What is the primary goal of designing a research study?
In the context of research design, what does a 'predictor variable' relate to?
In the context of research design, what does a 'predictor variable' relate to?
What is the main purpose of the decision tree approach described in the lecture?
What is the main purpose of the decision tree approach described in the lecture?
According to the learning framework, what is the first consideration when selecting an appropriate statistical test?
According to the learning framework, what is the first consideration when selecting an appropriate statistical test?
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What is the intended outcome of using a decision tree in statistical analysis?
What is the intended outcome of using a decision tree in statistical analysis?
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What is the primary focus of the practical sessions in the course?
What is the primary focus of the practical sessions in the course?
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Which of the following best describes the overall aim of the course?
Which of the following best describes the overall aim of the course?
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What is the role of statistics in the research process according to this learning material?
What is the role of statistics in the research process according to this learning material?
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Which statistical test is most appropriate when comparing the means of two independent groups and the data meet the assumptions of a parametric test?
Which statistical test is most appropriate when comparing the means of two independent groups and the data meet the assumptions of a parametric test?
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Which type of statistical analysis is BEST suited for examining the relationship between two continuous variables, assuming no manipulation of variables?
Which type of statistical analysis is BEST suited for examining the relationship between two continuous variables, assuming no manipulation of variables?
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When would a repeated measures ANOVA be an appropriate statistical test?
When would a repeated measures ANOVA be an appropriate statistical test?
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If you have a non-parametric data set used to compare two measures, which test would be the appropriate one to use?
If you have a non-parametric data set used to compare two measures, which test would be the appropriate one to use?
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What type of variable is characterized by equal intervals that represent equal differences in the measured property?
What type of variable is characterized by equal intervals that represent equal differences in the measured property?
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Which statistical method is used when predicting a binary outcome?
Which statistical method is used when predicting a binary outcome?
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If you are comparing multiple groups for a non-parametric data set, which statistical test should be used?
If you are comparing multiple groups for a non-parametric data set, which statistical test should be used?
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Which variable type is characterized by categories with no inherent order?
Which variable type is characterized by categories with no inherent order?
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What type of research design would require the use of a factorial ANOVA?
What type of research design would require the use of a factorial ANOVA?
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If you have two sets of measurements of the same individuals, and your data does not meet the criteria for use of parametric statistics, what statistical test should be used?
If you have two sets of measurements of the same individuals, and your data does not meet the criteria for use of parametric statistics, what statistical test should be used?
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What type of variable is characterized by categories with a logical, incremental order?
What type of variable is characterized by categories with a logical, incremental order?
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Which of the following best describes a ratio variable?
Which of the following best describes a ratio variable?
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If a researcher measures height in centimeters, what type of variable are they using?
If a researcher measures height in centimeters, what type of variable are they using?
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A study categorizes participants as either 'omnivore', 'vegetarian', 'vegan', or 'fruitarian'. What type of variable is this?
A study categorizes participants as either 'omnivore', 'vegetarian', 'vegan', or 'fruitarian'. What type of variable is this?
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In the context of statistical analysis, what is a key factor that influences the selection of a statistical test?
In the context of statistical analysis, what is a key factor that influences the selection of a statistical test?
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According to the provided decision tree, what is the first step in determining your learning framework?
According to the provided decision tree, what is the first step in determining your learning framework?
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What is the primary difference between interval and ratio variables?
What is the primary difference between interval and ratio variables?
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A research study uses a Likert scale to measure satisfaction, which is then treated as a continuous variable after inspecting the data distribution. Which of the following is most likely true?
A research study uses a Likert scale to measure satisfaction, which is then treated as a continuous variable after inspecting the data distribution. Which of the following is most likely true?
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Which conclusion is supported if several studies on antiSTATic show mixed results, with some showing a significant effect and others showing no effect?
Which conclusion is supported if several studies on antiSTATic show mixed results, with some showing a significant effect and others showing no effect?
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If a majority of studies find no significant effect of antiSTATic compared to a placebo, how should its effectiveness be interpreted on balance?
If a majority of studies find no significant effect of antiSTATic compared to a placebo, how should its effectiveness be interpreted on balance?
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What does it mean for a research finding to be described as 'equivocal'?
What does it mean for a research finding to be described as 'equivocal'?
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How should researchers approach studies where some results are significant (p<0.05) and others are not?
How should researchers approach studies where some results are significant (p<0.05) and others are not?
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What is the main idea conveyed by the statement: 'I want to go for C, but I have a feeling it’s a trick question'?
What is the main idea conveyed by the statement: 'I want to go for C, but I have a feeling it’s a trick question'?
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Which of the following is NOT a characteristic of a normal distribution?
Which of the following is NOT a characteristic of a normal distribution?
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In a positively skewed distribution, how do the mean, median, and mode typically relate?
In a positively skewed distribution, how do the mean, median, and mode typically relate?
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What does the term 'kurtosis' refer to in the context of a distribution's shape?
What does the term 'kurtosis' refer to in the context of a distribution's shape?
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Which measure of central tendency is most susceptible to sample fluctuations and not recommended as the sole measure?
Which measure of central tendency is most susceptible to sample fluctuations and not recommended as the sole measure?
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Which measure of central tendency is most appropriate for skewed distributions?
Which measure of central tendency is most appropriate for skewed distributions?
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If a distribution has a shape described as 'platykurtic', what does this indicate?
If a distribution has a shape described as 'platykurtic', what does this indicate?
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For a symmetrical distribution, what is the relationship between the mean, median, and mode?
For a symmetrical distribution, what is the relationship between the mean, median, and mode?
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Which measure of central tendency can be used with nominal data?
Which measure of central tendency can be used with nominal data?
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What does the term 'validity' refer to in the context of measurement?
What does the term 'validity' refer to in the context of measurement?
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Which of the following best describes 'test-retest reliability'?
Which of the following best describes 'test-retest reliability'?
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Systematic variation in experimental data is best described as:
Systematic variation in experimental data is best described as:
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In research design, what is the key distinction between an independent variable and a dependent variable?
In research design, what is the key distinction between an independent variable and a dependent variable?
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What does the null hypothesis in Null Hypothesis Significance Testing (NHST) propose?
What does the null hypothesis in Null Hypothesis Significance Testing (NHST) propose?
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In NHST, what does the P-value represent?
In NHST, what does the P-value represent?
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A directional hypothesis, compared to a non-directional one, specifically predicts:
A directional hypothesis, compared to a non-directional one, specifically predicts:
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Which of the following is a common misconception about statistical significance?
Which of the following is a common misconception about statistical significance?
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What is the 'all-or-nothing' thinking problem associated with p-values?
What is the 'all-or-nothing' thinking problem associated with p-values?
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What does 'unsystematic variation' typically include?
What does 'unsystematic variation' typically include?
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Flashcards
What sort of measurement?
What sort of measurement?
The type of data being measured, either continuous (e.g., height, weight) or categorical (e.g., gender, colour).
How many predictor variables?
How many predictor variables?
The number of variables that are influencing or predicting the outcome, for example, if you are looking at the effect of age and gender on reaction time, you would have two predictor variables.
What is the hypothesis?
What is the hypothesis?
The hypothesis that is being tested using statistical analysis. It usually proposes a relationship between variables.
What statistical approach to use?
What statistical approach to use?
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How is the study designed?
How is the study designed?
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How is data collected?
How is data collected?
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How is data analyzed?
How is data analyzed?
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What conclusions are drawn?
What conclusions are drawn?
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Interval Variable
Interval Variable
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Ordinal Variable
Ordinal Variable
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Nominal Variable
Nominal Variable
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Continuous Variable
Continuous Variable
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Predictor Variables
Predictor Variables
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Outcome Variable
Outcome Variable
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Decision Tree
Decision Tree
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Categorical Variable
Categorical Variable
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Independent Samples t-test
Independent Samples t-test
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Dependent Samples t-test
Dependent Samples t-test
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One-Way ANOVA
One-Way ANOVA
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One-Way Repeated Measures ANOVA
One-Way Repeated Measures ANOVA
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Pearson Correlation
Pearson Correlation
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Spearman Correlation
Spearman Correlation
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Equivocal Evidence
Equivocal Evidence
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Mean Difference
Mean Difference
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Significant Result (p<0.05)
Significant Result (p<0.05)
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Control Group
Control Group
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Inconclusive Studies
Inconclusive Studies
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Validity
Validity
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Reliability
Reliability
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Test-Retest Reliability
Test-Retest Reliability
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Systematic Variation
Systematic Variation
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Unsystematic Variation
Unsystematic Variation
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Randomization
Randomization
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Independent Variable
Independent Variable
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Dependent Variable
Dependent Variable
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Null Hypothesis
Null Hypothesis
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Alternative Hypothesis
Alternative Hypothesis
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Normal Distribution
Normal Distribution
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Parameters of Normal Distribution
Parameters of Normal Distribution
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Mean
Mean
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Standard Deviation
Standard Deviation
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Symmetry
Symmetry
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Skewness
Skewness
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Kurtosis
Kurtosis
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Bell-shaped
Bell-shaped
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Study Notes
Research Design and Statistics (RDS)
- The course covers research design and statistics
- Instructor is Tony Morland
- Email is [email protected]
- Research interests center on the structural, functional, and chemical properties of the brain linked to human vision, both in health and disease.
- Teaches MSc Research Design and Statistics, Topics in Cognitive Neuroscience, and provides project supervision.
Learning Outcomes
- Lectures: Focus on basic statistics theory and its application, understanding various research designs, and the rationale behind different methods. Students will further learn to interpret empirical studies, including their own.
- Practicals: Include performing relevant statistical tests using SPSS and interpreting empirical data. Viewing the videos is vital to completing the practical components.
- Overall: Aim to build confidence in choosing the most effective data analysis method, even if it is not a familiar approach.
Design and Statistics
- Begins with a question or hypothesis about a population.
- A study is proposed to gather data to test the hypothesis.
- Study design is optimized to gain the most valuable information about the hypothesis.
- Data is collected (sampling from the population).
- Statistics are used to test the hypothesis, basing analysis on a model of the data.
- Results are examined and interpreted.
Learning Framework
- A decision tree framework is presented to clarify which statistical approach is appropriate given certain situations.
- Decision-making follows from a series of key questions.
- Each path within the decision tree leads to a particular statistical approach.
Decision Tree - Learning Framework
- Steps in the decision tree to choose statistical approach
- Categorization of measurement types (continuous vs. categorical)
- Number of predictor variables
- Predictor variable type
- Levels of categorical predictors
- Similarity/Differences in participants (Same or different people for each predictor measure)
- Using SPSS
- Statistical tests from that tree. (e.g., t-test, ANOVA, regression, chi-square, and others)
Analogy
- Statistical tests are tools.
- Correct tool use depends on the type of data collected (analogous to using a hammer for nails, a screwdriver for screws, etc.).
Measuring and Measurements
- Research starts with a question or hypothesis.
- Data is collected in the form of outcomes, to test the hypothesis.
- Multiple outcomes can be collected from the same group of people and/or under different conditions (groups).
- The specifics of measurement and the conditions under which measurements are taken are critical to the experimental design/study.
Types of Outcomes
- Outcomes are measured in categories; examples are: ratio, interval, ordinal, nominal.
Continuous Variables
- Continuous variables can take on a wide range of values.
- Interval variables: Intervals represent equal differences. (e.g., the difference between 600 ms and 800 ms is equivalent to the difference between 1300 ms and 1500 ms.)
- Ratio variables: Interval variables with a true zero point (e.g., participant height or weight).
Categorical Variables
- Categorical variables represent distinct categories (e.g., omnivore, vegetarian, or fruitarian.).
- Nominal variables: Categories have no inherent order (e.g., eye color).
- Ordinal variables: Categories have an order (e.g., levels of agreement on a Likert scale).
A Thing About Outcomes: Measurement Error
- Involves the difference between the actual value being measured and the measured value.
- Values need consistent meaning across time and situations.
- Validity: Instruments measure what they should.
- Reliability: Instruments produce similar results under the same conditions (test–retest reliability).
Types of Variations
- Systematic variation: Differences in performance due to specific experimental manipulations.
- Unsystematic variation: Differences in performance due to unknown factors. (e.g., age, gender, IQ, time of day).
- Minimizing unsystematic variation is important for reliable measurement.
Nomenclature of Variables in Design
- Independent Variable (IV): Hypothesized cause (predictor variable). Can be manipulated (e.g., in experiments).
- Dependent Variable (DV): Proposed effect (outcome variable). It is measured, not manipulated.
Inferential Statistics
- Null Hypothesis Significance Testing (NHST):
- Assesses the probability of the null hypothesis being true (referred to as the P-value).
- Two sets of hypotheses are typically involved: the null hypothesis and the alternative hypothesis.
- Directional and non directional hypotheses are discussed.
Issues with Null Hypothesis Significance Testing (NHST)
- Some misconceptions in NHST interpretation:
- Significant result = important effect.
- Non-significant result = null hypothesis is true.
- Significant result = null hypothesis is false.
- P-hacking and HARKING are problems to look out for (degrees of freedom for exploration after data collection)
All is not Lost: EMBERS
- Effect sizes: Quantify the magnitude of an effect (not just whether it is statistically significant).
- Meta-analysis: Combines findings from multiple studies.
- Bayesian Estimation: Computes the probabilities of different hypotheses given the data.
- Registration: Researchers publicly commit to analyses before data collection.
- Sense: Using common sense and being aware of potential issues in research.
EMBERS Details
- E (Effect size): Measure of the strength of an effect. Cohen's d is mentioned as an example.
- M (Meta-analysis): Combining results from multiple studies, addressing inconsistency across studies. Funnel plots can reveal publication bias.
- B (Bayesian): Bayesian approaches, offering a more nuanced view of the strength of evidence.
- R (Registration): Pre-registration, where researchers disclose their methods and analysis plan before data collection.
- S (Sense): Critical consideration of outcomes in the context of NHST, and measures to address researcher biases.
Descriptive Statistics of Outcomes
- How data are distributed is important.
- How to assess the distribution of data and associated methods.
What Distribution is Needed for Parametric Tests?
- The data should come from a normal distribution.
- Characteristics of the normal distribution:
- Bell-shaped curve
- Symmetrical
- Defined by mean (central tendency) and standard deviation (dispersion).
How do we know what is normal?
- Use statistical approaches such as the Kolmogorov–Smirnov test and the Shapiro–Wilks test to assess the normality of the data.
- Plotting the data is very important.
What was done this week?
- Introduction to Research Design and Inferential Statistics.
- Learning how outcomes influence the approach.
- Logic of Null Hypothesis Significance Testing and its associated pitfalls.
- Evaluating data normality, and how descriptive statistics contribute to the analysis.
Practical Week 1:
- Introduction to data entry and manipulation in SPSS.
- Computing descriptive statistics.
- Plotting data
- Testing assumptions for parametric tests.
What’s next week?
- Extending descriptive statistics knowledge.
- Hypothesis testing understanding.
- Data plotting/presentation.
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Description
Test your understanding of key concepts in research design and statistics with this quiz. Explore the roles of variables, statistical tests, and decision-making approaches as outlined in the course material. Perfect for students looking to solidify their knowledge in research methodologies.