Design and Analysis of Single-Case Research

By Ronald D. Franklin; David B. Allison et al. | Go to book overview

TABLE 10.5
Effect Size (d)Total NAnalytic PowerEarly NActual Power
.20 790 .799 682 .827
.30 350 .794 301 .829
.50 130 .793 112 .799
.80 50 .753 44 .825
1.00 40 .823 35 .863

3.00; in other words, at .0027. The study is stopped when the null hypothesis of no difference between conditions can be rejected or when the maximum duration is reached, whichever occurs first. Via Monte Carlo simulation, we computed the total Type-I error probability for this procedure. Using a nominal α of .05, the total a was only .0599. Table 10.5 shows some representative results from simulations we conducted under various alternative hypotheses. Effect size is expressed as the standardized mean difference (d); total N is the total number of observations required to achieve the level of power labeled "analytic power," calculated with standard power analysis software ( Gorman, Primavera, & Allison, 1995); early N is the average number of observations that actually needed to be collected over 1,000 simulated experiments; and actual power is the proportion of times a significant result occurred over the 1,000 simulations.

What is apparent is that the power is slightly greater with the early stopping rule and, more important, there is an average saving of approximately 12% on trial costs. Berntsen et al. ( 1991) discussed the possibility of further reducing average trial costs by incorporating "futility tests" in which one can abandon a trial midway through when interim analyses suggest that there is virtually no chance of obtaining a significant result, even if the trial was extended to its maximum.

Of course, it should be noted that the exact results reported here apply only to the particular early stopping rule described. But the point is that judicious use of an appropriate stopping rule often will reduce the total number of required observations.


SUMMARY

In conclusion, it can be seen that there is no substitute for a well-designed, well-powered study. The prudent investigator will devote as much time to statistically planning his or her study as to analyzing the study. We hope that this chapter makes the task a bit more tractable.

-367-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this book

This book has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this book

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited page

Bookmark this page
Design and Analysis of Single-Case Research
Table of contents

Table of contents

  • Title Page iii
  • Contents v
  • Preface vii
  • References x
  • Contributors xiii
  • List of Equations xix
  • 1: Introduction 1
  • Introduction 1
  • References 10
  • 2: Historical and Philosophical Foundations of Single-Case Research 13
  • References 39
  • 3: Measurement of Dependent Variables 41
  • References 84
  • APPENDIX: CONSTRUCTING CONFIDENCE INTERVALS FOR ICCS (FROM SHROUT & FLEISS, 1979) 90
  • 4: Treatment Integrity in Single-Subject Research 93
  • 5: Graphical Display and Visual Analysis1 119
  • Introduction 119
  • References 154
  • 6: Statistical Alternatives for Single-Case Designs 159
  • References 208
  • 7: Serial Dependency in Single-Case Time Series 215
  • Introduction 215
  • References 242
  • 8: Meta-Analysis of Single-Case Research 245
  • Introduction 245
  • SUMMARY 273
  • References 273
  • 9: The Potentially Confounding Effects of Cyclicity: Identification, Prevention, and Control 279
  • References 328
  • Appendix 334
  • 10: Power, Sample Size Estimation, and Early Stopping Rules 335
  • Introduction 335
  • SUMMARY 367
  • References 368
  • Author Index 373
  • Subject Index 383
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
/ 394

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

    Already a member? Log in now.