aipe.smd | R Documentation |

A set of functions that `ss.aipe.smd`

calls upon to calculate the appropriate sample size
for the standardized mean difference such that the expected value of the confidence interval
is sufficiently narrow.

ss.aipe.smd.full(delta, conf.level, width, ...) ss.aipe.smd.lower(delta, conf.level, width, ...) ss.aipe.smd.upper(delta, conf.level, width, ...)

`delta` |
the population value of the standardized mean difference |

`conf.level` |
the desired degree of confidence (i.e., 1-Type I error rate) |

`width` |
desired width of the specified (i.e., |

`...` |
specify additional parameters in functions these functions call upon |

`n` |
The necessary sample size |

The returned value is the sample size *per group*. Currently only
`ss.aipe.smd.full`

returns the exact value. However, `ss.aipe.smd.lower`

and `ss.aipe.smd.upper`

provide approximate sample size values.

The function `ss.aipe.smd`

is the function users should generally use. The function
`ss.aipe.smd`

calls upon these functions as needed. They can be thought of loosely
as internal MBESS functions.

Ken Kelley (University of Notre Dame; KKelley@ND.Edu)

Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Erlbaum.

Cumming, G. & Finch, S. (2001). A primer on the understanding, use, and calculation of confidence intervals that are
based on central and noncentral distributions, *Educational and Psychological Measurement, 61*, 532–574.

Hedges, L. V. (1981). Distribution theory for Glass's Estimator of effect size and related estimators. *Journal of Educational Statistics, 2*, 107–128.

Kelley, K. (2005). The effects of nonnormal distributions on confidence intervals around the standardized mean
difference: Bootstrap and parametric confidence intervals, *Educational and Psychological Measurement, 65*, 51–69.

Kelley, K., Maxwell, S. E., & Rausch, J. R. (2003). Obtaining Power or Obtaining Precision: Delineating Methods
of Sample-Size Planning, *Evaluation and the Health Professions, 26*, 258–287.

Kelley, K., & Rausch, J. R. (2006). Sample size planning for the standardized mean difference:
Accuracy in Parameter Estimation via narrow confidence intervals. *Psychological Methods, 11(4)*, 363–385.

Steiger, J. H., & Fouladi, R. T. (1997). Noncentrality interval estimation and the evaluation of
statistical methods. In L. L. Harlow, S. A. Mulaik, & J.H. Steiger (Eds.), *What if there were
no significance tests?* (pp. 221–257). Mahwah, NJ: Lawrence Erlbaum.

`ss.aipe.smd`

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