NCSS
Statistical & Power Analysis Software
 

Home   Order   Downloads   Support   News   Contact Us   Site Map

 
 Product Links
    Home
    PASS Home
     - Procedure List
     - Upgrade Info
    NCSS Home
     - Procedure List
     - Upgrade Info
    GESS Home
     - Procedure List
   
 Downloads
    Downloads
    - Free Trial
    - PASS 2008
    - NCSS 2007
    - Updates
    - Manuals
   
 Order
    Order Online
    PDF Order Forms
    Price Lists
   
 Questions
    Support
    FAQ
   
 Brochures
    PASS
    PASS Upgrade
    NCSS
    NCSS Upgrade
    GESS
   
 Information
    About NCSS
    Contact Us
    News
    Site Map
   

 

PASS
Power Analysis and Sample Size

The Best Power Analysis Software on the Market

Power Analysis
A statistical test's power is the probability that the test procedure will result in statistical significance. Power is related to the sample size, the size of the type I (alpha) error, the actual size of the effect, and the size of experimental error. All of these must be considered in order to calculate statistical power.

As statistical significance is usually the desired outcome, planning and running a study to achieve a high power is of prime importance to the researcher. Because of the complexity of the calculations, the determination of the power is often ignored or only a casual attempt is made at its calculation by adopting some, so-called, "rule-of-thumb."

PASS Beats the Competition!
PASS performs power analysis and calculates sample sizes. Use it before you begin a study to calculate an appropriate sample size (it meets the requirements of government agencies that demand technical justification of the sample size you have used). Use it after a study to determine if your sample size was large enough.

PASS lets you solve for power, sample size, effect size, and alpha level. It  automatically displays charts and graphs along with numeric tables and text summaries in a portable format that is cut and paste compatible with all word processors so you can easily include the results in your proposal.

PASS is a standalone system. Although it is integrated with NCSS, you do not have to own NCSS to run it. You can use it with any statistical software you want. PASS 2008 runs under Windows Vista, XP, 2000, NT, ME, 98, and 95.

PASS is accurate. It has been extensively verified using books and reference articles. Proof of the accuracy of each procedure is included in the extensive documentation.

PASS comes with three manuals that contain tutorials, examples, annotated output, references, formulas, verification, and complete instructions on each procedure. And, if you cannot find an answer in the manual, our free technical support staff (which includes three PhD statisticians) is available.

No other program calculates sample sizes and power for as many different statistical procedures as does PASS. Specifying your input is easy, especially with the online help and manual.

Choose PASS. It's more comprehensive, easier-to-use, accurate, and less expensive than any other sample size program on the market.

Features. PASS is the most comprehensive sample size program available with over 150 statistical procedures. Accuracy of each procedures is well validated. PASS is easy to learn and use. PASS is a standalone software package (no other stat package is required). PASS easily produces sharp, flexible graphics. PASS output is easily transferred to popular word processors and presentation software such as PowerPoint.

Pricing. With electronic documentation, PASS 2008 sells for $749.95 (academic/government) and $999.95 (commercial), a price much lower than the competition's. With printed manuals, PASS 2008 sells for $849.95 (academic/government) and $1,099.95 (commercial). We also offer special pricing for current students. Call for details. Multiple-user discounts are also available. You can order from our secure online order form, by email, by fax, or over the phone.

7-Day Trial. Go ahead, download a 7-day trial version of PASS today. During the trial period, the spreadsheet is limited to 100 rows of data. You can try all of the statistical procedures, import/export your data, and print your reports. This is an excellent way to become acquainted with PASS.

 
 

PASS 2008
Upgrade Available


from PASS 2005:
$349.95 (academic/gov)
$399.95 (commercial)

from Earlier Versions:
$449.95 (academic/gov)
$499.95 (commercial)

We are pleased to announce the availability of PASS 2008. This edition adds over 40 new procedures and features to PASS.

New Procedures
Mixed Models
Logrank (Survival) Tests
Logrank Non-Inferiority Tests
Randomization Lists
Kappa Test for Agreement
CI - Means (6 Procedures)
CI - Proportions (2 Procedures)
CI - Regression Slope
CI - SD/Variance
  (8 Procedures)

CI - Correlation
Microarray One-Sample/Paired
  T-Tests

Microarray Two-Sample
  T-Tests

Proportion Trend Tests
Normality Tests
TAD - Two Means
TAD - Two Proportions
Design of Experiments
  (9 Procedures)

New Features
Simplified Interface
Improved Help System
Quick Launch
Macros (Programmability)

Upgrade Now

Read about what’s new in PASS 2008.

View the upgrade brochure.
View the PASS 2008 brochure.


Download a PASS Update
Current Version:
PASS 2008
Released May 13, 2008

Update

What's changed in this release?


Sample PASS Procedures & Reports

Click here for the complete list.

Equivalence
    Correlated proportions
    Cross-over designs
    One proportion
Group Sequential Tests
Logrank (Survival) Tests
Means - 1 or 2 Groups (T-tests)
    Simulation
Means - Confidence Intervals
Means - Correlated or Paired
    Simulation
Means - Cross-Over Designs
    2x2 designs
    Balaam’s design
    Higher-order designs
Means - Many (ANOVA)
    MANOVA
    Repeated Measures
    Simulation
Mixed Models
Non-Inferiority
    Correlated proportions
Normality Tests
Probability Calculator
Proportion - 1 Group
    Equivalence tests
    Inequality tests
    Non-inferiority tests

Proportions - 2 Groups
    Cluster-randomization
    Equivalence tests
    Inequality tests
    Mantel-Haenszel test
    Non-inferiority tests
Proportions - Confidence Intervals
Proportions - Correlated or Paired
Proportions - Many Groups
Randomization Lists
Regression/Correlation
    Coefficient alpha
    Cronbach’s alpha
ROC Curves
Special Calculators
Survival Analysis
    Cox regression
Variances


Reviewer’s Comments

“For graphics production, PASS is the most flexible, allowing plots of any variable against any other, grouped by a third.”
“Seventeen out of 19 students rated PASS as the package they would recommend first to their colleagues.”

- Len Thomas & Charles Krebs in “A Review of Statistical Power Analysis Software”
ESA Bulletin, 1997.

 

Download a 7-day trial copy of PASS 2008

Download

Place an order using our secure online order form

Buy Now

 


PASS Home
PASS is easy to navigate with a simple procedure selection window. Simply scroll down the list and expand the tree to find the procedure you want. A message on the right gives an explanation of each procedure.


Procedure Window
Once you select a procedure from the tree or menus, the corresponding Procedure Window appears. This window lets you quickly and easily specify the power analysis or sample size parameters. The immediate help window on the right gives you a brief explanation of each option as the mouse passes over it. You can save the settings in a template file for future use.


Output

All reports are displayed using our built-in Word Processor. You can quickly view, edit, save, and print your output. Reports are stored in the generic RTF (rich text) format that can be read by most word processors, so you can easily save PASS reports for further use in Word or WordPerfect. The output document mixes text and graphs together. The text portions of the reports are formatted using tabs (not spaces), so they are easily reformatted.

 
   

System Requirements
Runs under Windows Vista, XP, 2000, NT, ME, 98, 95 compatible Pentium-class computers with at least 32 MB of RAM. Requires 200 MB of hard disk space. Requires Adobe Reader® version 7 or later to use the NCSS, PASS, and GESS Help Systems.
Accuracy
We at NCSS have put a great deal of effort into finding the most accurate algorithms possible. The programs have been tested and verified over and over, both by us and by our customers. Each routine has been verified against textbooks, journal articles, and, where possible, other software. This verification is given in the documentation. PASS calculates with seventeen-digit, double-precision accuracy.
Guarantee
If you are not completely satisfied with PASS during the first 30 days for any reason, return the program for a full, prompt refund (excluding shipping)--no questions asked.
 

Home | Order | Downloads | Support | News | Contact Us | Site Map

NCSS • 329 North 1000 East • Kaysville, Utah 84037 • USA
Email: sales@ncss.com   Phone: (801) 546-0445   Toll Free: 1-800-898-6109   Fax: (801) 546-3907