Design Resources Server

Analysis of Data from Designed Experiments

 Tests of Significance Based on T - Distribution

IASRI
Home

                        <<Back

                                                                                                                                                                                      Analysis Using SAS

Analysis Using MS-EXCEL

Analysis  Using  SPSS

Main Procedure is:  

Start →All Programs → SPSS for Windows → SPSS 15.0/ SPSS13.0/ SPSS10.0 (based on the version available on your machine) → Enter data in Data Editor → Analyze → Compare means → Independent-Samples T test → group [puts group under Grouping Variable: ] tmfppp → nfs45 → fw → fl → syp → sl [puts tmfppp, nfs45, fw,  fl,  syp,  sl under Test Variables(s): ] →   Define Groups →  Continue → Run All.

For performing analysis, input the data in the following format. 

{Here Total number of male flowers per plant is termed as tmfppp, Number of  fruit (45 days) is termed as nfs45, Fruit weight (kg) is termed as fw, Fruit length(cm) is termed as fl, seed yield/plant (g) is termed as syp and Seedling length (cm) is termed as sl. It may, however, be noted that one can retain the same name or can code in any other fashion}.

 Following are the brief description of the steps along with screen shots.

·         Open Data editor: Start All Programs SPSS for Windows SPSS 15.0/ SPSS13.0/ SPSS10.0

  • Enter data in SPSS Data Editor. There are two views in SPSS Data Editor. In variable view, one can define the name of variables and variable types string or numeric and data view gives the spreadsheet in which data pertaining to variables may be entered in respective columns. In the present case, we enter data in numeric format

·         Once the data entry is complete, Choose Analyze from the Menu Bar. Now select Analyze → Compare Means → Independent-Samples T Test.

  • This selection displays the following screen

·         Select group and send it to the Grouping Variables box; tmfppp, nfs45, fw,  fl,  syp,  sl under Test Variables(s) box. After doing these the dialog box should be like this

·                   Select Define Groups in the Independent-Samples T Test dialog box i.e. Define Groups… [Opens Define Group dialogue box] → Use Specified values Define Groups as 2 and 3. This selection displays the following screen.

·         Click Continue to return to the Independent-Samples T Test dialog box.

 

  • Click OK.

To answer the question number 2 one has to perform by the one tail t-test. The easiest way to convert a two-tailed test into a one-tailed test is to take half of the p-value provided in the output of 2-tailed test  for drawing inferences.  

To answer the questions 1 the following syntax may be used after creating the data file.

T-TEST

  GROUPS = group(2 3)

  /MISSING = ANALYSIS

  /VARIABLES = tmfppp nfs45 fw fl syp sl

  /CRITERIA = CI(.95) .  

 

 

 

Data File

Syntax File

Result File

 

                                                                                                                                                                                 <<Back

Analysis Using SAS                       Analysis Using SPSS                     Analysis Using MS-EXCEL                      

 

 

 

Home Descriptive Statistics  Tests of Significance Correlation and Regression Completely Randomised Design  RCB Design  

Incomplete Block Design  Resolvable Block Design  Augmented Design  Latin Square Design Factorial RCB Design  

Partially Confounded Design Factorial Experiment with Extra Treatments Split Plot Design Strip Plot Design 

Response Surface Design Cross Over Design  Analysis of Covariance Diagnostics and Remedial Measures 

Principal Component Analysis Cluster Analysis Groups of Experiments  Non-Linear Models  

Contact Us

    

 

 

 

  Copyright        Disclaimer        How to Quote this page        Report Error        Comments/suggestions 

Descriptive Statistics
Tests of Significance
Correlation and Regression
Completely Randomised Design
RCB Design
Incomplete Block Design
Resolvable Block Design
Augmented Design
Latin Square Design
Factorial RCB Design
Partially Confounded Design
Factorial Experiment with Extra Treatments
Split Plot Design
Strip Plot Design
Response Surface Design
Cross Over Design
Analysis of Covariance
Diagnostics and Remedial Measures
Principal Component Analysis
Cluster Analysis
Groups of Experiments
Non-Linear Models
Contact Us
Other Designed Experiments
   
(Under Development)

For exposure on SAS, SPSS, 
MINITAB, SYSTAT and
 
MS-EXCEL for analysis of data from designed experiments:

 Please see Module I of Electronic Book II: Advances in Data Analytical Techniques

available at Design Resource Server (www.iasri.res.in/design)