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| For a theoretical background and details of specialist software have a look at graduate seminar on power at the [:StatsCourse2006:Graduate Statistics Programme October-December 2006]. There is also [http://homepages.gold.ac.uk/aphome/cc16work.doc a worked example] using "Method 2" on a t-test. | For a theoretical background and details of specialist software have a look at graduate seminar on power at the [[StatsCourse2006|Graduate Statistics Programme October-December 2006]]. There is also [[http://homepages.gold.ac.uk/aphome/cc16work.doc|a worked example]] using "Method 2" on a t-test. |
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| * [:FAQ/power/onesamp:One sample t-test] | * [[FAQ/power/onesamp|One sample t-test]] |
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| * [:FAQ/power/unpaired:Unpaired t-tests (equal group sizes)] | * [[FAQ/power/unpaired|Unpaired t-tests (equal group sizes)]] |
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| * [:FAQ/power/unpairedUneq:Unpaired t-tests (unequal group sizes)] | * [[FAQ/power/unpairedUneq|Unpaired t-tests (unequal group sizes)]] |
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| * [:FAQ/power/pairt:Paired t-tests] | * [[FAQ/power/pairt|Paired t-tests]] |
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| * [:FAQ/power/owAnovaN:Regression including One-Way ANOVA and ANCOVA] | * [[FAQ/power/owAnovaN|Regression including One-Way ANOVA and ANCOVA]] |
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| * [:FAQ/power/pPowN: Comparing a single proportion with a constant (sign test)] | * [[FAQ/power/pPowN| Comparing a single proportion with a constant (sign test)]] |
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| * [:FAQ/power/propsn: Comparing two independent proportions] | * [[FAQ/power/propsn| Comparing two independent proportions]] |
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| * [:FAQ/power/prop1sn:Comparing three or more independent proportions] | * [[FAQ/power/prop1sn|Comparing three or more independent proportions]] |
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| * [:FAQ/power/mcn: Comparing two related proportions (McNemar test)] | * [[FAQ/power/mcn| Comparing two related proportions (McNemar test)]] |
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| * [:FAQ/power/FisherrN: Comparing two independent correlations from two different samples] | * [[FAQ/power/FisherrN| Comparing two independent correlations from two different samples]] |
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| * [:FAQ/power/rmPowN: A term in any Anova (including repeated measures)] | * [[FAQ/power/rmPowN| A term in any Anova (including repeated measures)]] |
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| * [:FAQ/power/llogN: A single predictor in a multiple binary logistic regression] | * [[FAQ/power/llogN| A single predictor in a multiple binary logistic regression]] |
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| * [:FAQ/power/hazN: Survival analysis] | * [[FAQ/power/hazN| Survival analysis]] |
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| * [:FAQ/power/onesampn:One sample t-test] | * [[FAQ/power/onesampn|One sample t-test]] |
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| * [:FAQ/power/unpaireqn:Unpaired t-tests (equal group sizes)] | * [[FAQ/power/unpaireqn|Unpaired t-tests (equal group sizes)]] |
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| * [:FAQ/power/unpairn:Unpaired t-tests (unequal group sizes)] | * [[FAQ/power/unpairn|Unpaired t-tests (unequal group sizes)]] |
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| * [:FAQ/power/pairn:Paired t-tests] | * [[FAQ/power/pairn|Paired t-tests]] |
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| * [:FAQ/power/owanova:Regression including One-Way ANOVA and ANCOVA] | * [[FAQ/power/owanova|Regression including One-Way ANOVA and ANCOVA]] |
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| * [:FAQ/power/pPow: Comparing a single proportion with a constant (sign test)] | * [[FAQ/power/pPow| Comparing a single proportion with a constant (sign test)]] |
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| * [:FAQ/power/props:Comparing two independent proportions] | * [[FAQ/power/props|Comparing two independent proportions]] |
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| * [:FAQ/power/prop1s:Comparing three or more independent proportions] | * [[FAQ/power/prop1s|Comparing three or more independent proportions]] |
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| * [:FAQ/power/mcnemarN: Comparing two related proportions (McNemar test)] | * [[FAQ/power/mcnemarN| Comparing two related proportions (McNemar test)]] |
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| * [:FAQ/power/Fisherr: Comparing two independent correlations from two different samples] | * [[FAQ/power/Fisherr| Comparing two independent correlations from two different samples]] |
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| * [:FAQ/power/rmPow:A term in any Anova (including repeated measures)] | * [[FAQ/power/rmPow|A term in any Anova (including repeated measures)]] |
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| * [:FAQ/power/llogPow: A single predictor in a multiple binary logistic regression] | * [[FAQ/power/llogPow| A single predictor in a multiple binary logistic regression]] |
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| * [:FAQ/power/haz: Survival analysis] | * [[FAQ/power/haz| Survival analysis]] |
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| Additional power freeware (including the popular G*POWER (currently version 3)) is available for download from [http://www.epibiostat.ucsf.edu/biostat/sampsize.html#PCSize here.] Some examples using G*POWER 3 are in Howell (2013). | Additional power freeware (including the popular G*POWER (currently version 3)) is available for download from [[http://www.epibiostat.ucsf.edu/biostat/sampsize.html#PCSize|here.]] Some examples using G*POWER 3 are in Howell (2013). |
Power computations
Power computations can be performed in SPSS and R only using syntax. For SPSS users Chris Aberson has syntax for power calculations in his book. See reference below.
For a theoretical background and details of specialist software have a look at graduate seminar on power at the Graduate Statistics Programme October-December 2006. There is also a worked example using "Method 2" on a t-test.
Sample sizes required for a given power
Power required for given sample sizes
Additional power freeware (including the popular G*POWER (currently version 3)) is available for download from here. Some examples using G*POWER 3 are in Howell (2013).
References
Aberson CL (2010) Applied power analysis for the behavioral sciences. Routledge:London. This book contains examples of computing effect sizes and power using SPSS.
Howell DC (2013) Statistical methods for psychology. 8th Edition. International Edition. Wadsworth:Belmont,CA.