PSY302-300801922
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TESTS
Two-sample t-test: between (independent)
Definition: Testing the relationship between a categorical independent variable and a continuous independent variable, in which the categorical independent variable is a between-subjects design with two levels.
Example: http://linkinghub.elsevier.com/retrieve/pii/S0022399906002236
Application: Childhood trauma and anxiety creates more frequent trips to the physician.
Two-sample t-test: within (related)
Definition: Testing the relationship between a categorical independent variable and a continuous independent variable, in which the categorical independent variable is a within-subjects design with two levels.
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One-Way ANOVA test
Definition: Testing the relationship between a categorical independent variable and a continuous independent variable, in which the categorical independent variable is a between-subjects design with three or more levels.
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Two-Way ANOVA test
Definition: Testing the relationship between two categorical independent variable and a continuous independent variable.
Application: Eleven patients with focal cerebellar infarcts were studied prospectively after their injury to investigate everyday executive functioning abilities in patients with focal cerebellar lesions using an executive battery sensitive for the detection of damage to the prefrontal cortex. Tests that evolved throughout time were analysed using a two-way ANOVA with repeated measures
Correlation test
Definition: Testing the relationship between two continuous variables, either of which can be considered the independent or dependent variable.
Example:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2526388/
Application: the Korean version of the ACT was found to be a reliable and valid tool for measuring asthma control, and to correlate well with AQLQ scores. Moreover, the ACT was responsive to changes in AQLQ scores over time.
Chi-square test
Definition: Testing the relationship between two categorical variables, either of which can be considered the independent or dependent variable.
Example: http://www.jstor.org/stable/1126242?seq=1
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Concepts
Standard Score
Definition: A score obtained by using the transformation the z value formula.
Example: http://wrightslaw.com/advoc/articles/tests_measurements.html
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Confidence Interval
Definition: A range of score values expected to contain the value of mu with a certain level of confidence.
Application:A cross-sectional study was performed in February- March 2002, examining whether green tea consumption in everyday life in Japan is associated with positive mental health: with a 95% confidence interval the consumption of brewed green tea was not statistically associated with any decrease in risk of mental ill-health among either males or females Daily caffeine intake (100 mg) inclusive of green tea, black tea, coffee and other caffeine-containing beverages was associated with a higher risk of mental ill-health among females.
Parametric Test
Definition: A statistical test involving hypotheses that state a relationship about a population parameter.
Example: http://www3.interscience.wiley.com/cgi-bin/fulltext/119283021/PDFSTART
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Nonparametric Test
Definition: A statistical test involving hypotheses that do not state a relationship about a population parameter.
Example: http://www.springerlink.com/content/p7g2509616827241/fulltext.pdf
Application:Non-parametric tests were used to evaluate and investigate developmental and inter-individual differences in attention and reactivity to odors.
Statistically significant difference
Definition: The observed value of the test statistic falls into a rejection region and the Null Hypothesis is rejected.
Example: http://www.springerlink.com/content/e770741m7272781j/
Application: This article compares quality of life between people with chronic mental illness who use and do not use computer. Twenty-four participants were recruited from a medical center in northern Taiwan. There was no statistically significant difference in the physical, psychological and social relationship domains of quality of life.
Nonsignificant difference
Definition: The observed value of the test statistic does not fall into a rejection region and the Null Hypothesis is not rejected.
Example:http://www.springerlink.com/content/e770741m7272781j/
Application: This article compares quality of life between people with chronic mental illness who use and do not use computer. Twenty-four participants were recruited from a medical center in northern Taiwan. The results show that there was a statistically significant difference in environment domain of quality of life between people who use computers and people who do not use computers in their daily life
Between-subjects Design, with two groups
Definition: An experiment in which two or more groups are created.
Example: http://geronj.oxfordjournals.org/content/47/1/P41.abstract
Application:In experiment 2, a between-subjects design with 189 adults (mean age = 34 years) was employed to examine the generality of memory beliefs about age-related change and the anticipated slope. Secondary regression analyses revealed that participants with good memory self-perceptions anticipated better memory performance for others overall.
Between-subjects Design, with three or more groups
Definition:
Example:http://jpepsy.oxfordjournals.org/cgi/content/full/jsm101v1
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Random sampling
Definition: A sampling method in which individuals are selected so that each member of the population has an equal chance of being selected for the sample, and the selection of one member is independent of any other member of the population.
Example: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=141661
Application:This study investigated in a non-clinical population the interaction between cannabis use and psychosis vulnerability in their effects on psychotic experiences in daily life. Subjects (N = 79) with high or low levels of cannabis use were selected among a sample of 685 undergraduate university students.
Random Assignment
Definition: A method of assigning subjects to treatment groups so that any individual selected for the experiment has an equal probability of assignment to any of the groups and the assignment of one subject to a group does not affect the assignment of any other individual to that same group.
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Independent Variable
Definition: A variable manipulated in an experiment to determine its effect on the dependent variable.
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Levels of the Independent Variable
Definition: One value of the independent variable. To be a variable, an independent variable must take on at least two different levels.
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Confounds
Definition: An extraneous variable that is covarying with the independent variable, potentially masking the true effects of the independent variable on the dependent variable.
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Dependent Variable
Definition: The variable in an experiment that depends on the independent varialbe. (In most instances, DV in some measure of a behavior)
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Within-subjects Design, with two groups
Definition: A research design in which one group of subjects is exposed to and measured under each level of an independent variable. In a within-subjects design, each subject receives each treatment condition.
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Within-subjects Design, with three or more groups
Definition: A research design in which one group of subjects is exposed to and measured under each leve of the independent variable.
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Main effect
Definition: According to the text, it is the typical performance of all subjects given one level of an independent variable, ignoring the classifcation by the other independent variable.
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Interaction
Definition: A situation in a factorial design in which the effect of one independent variable depends on the level of the other independent variable with which it is combined.
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Strength of Effect (Eta squared)
Definition: A measurement of how much knowing the level of an independent variable that a subject received reduces the error in predicting the subject's score in the sample tested.
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Scatterplot
Definition: A plot of a bivariate distribution in which the X variable is plotted on the horizontal axis and the Y variable is plotted on the veritcal axis.
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Positive relationship
Definition: A relationship between two variables in which, as the value of one variable increases the value of the ohter variable tends to increase also.
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Negative relationship
Definition: A relationship between two variables in which, as the value of one variable increases, the value of the other variable tends to decrease.
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No relationship
Definition: No interaction/connection between variables observed.
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Linear relationship
Definition: A relationship between two variables that can be described by a straight line.
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Curvilinear relationship
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Coefficient of Determination
Definition: The value of the squared value of r, indicating the common variance of variables X and Y.
Application: Using a cross-sectional population-based survey, this article assessed the impact of premenstrual symptoms on activities of women's daily lives
Correlation does not equal causation
Definition: The fact that because variables correlate, does not mean that one variable causes another variable to occur, or vice versa.
Example: http://www.miller-mccune.com/health/the-cannabis-and-schizophrenia-conundrum-10218/?limit=1
Application:Scientists in Australia followed nearly 4,000 young adults born between 1981 and 1984 at the 21-year mark, and found that the longer study participants had used marijuana, the higher the risk of psychosis-related outcomes.
Extra-Credit (3 points each)
Normal Distribution
Symmetrical
Asymptotic
Continuous
Sampling Error
Null Hypothesis
Alternative Hypothesis
Significance level
Two-tailed test
One-tailed test
Degrees of Freedom
Type I Error
Type II Error
Power
Pairwise comparisons
Post-hoc comparisons
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