CD ROM Paradise Collection 4

home *** CD-ROM | disk | FTP | other *** search

/ CD ROM Paradise Collection 4 / CD ROM Paradise Collection 4 1995 Nov.iso / science / simst35.zip / INSTALL._D2 / INTRO.DOC < prev next >

Wrap

Text File | 1994-05-07 | 23KB | 461 lines

QUICK START Startup Options ~~~~~~~~~~~~~~~ Three startup options are available to change the SIMSTAT default settings. The following command line switches can be typed following the program name when calling SIMSTAT: /M (or -M) forces the program to run in black and white mode rather than in color. This option is useful for use with a laptop computer, or on a desktop computer with a monochrome or composite monitor set on a color graphic adapter (CGA, EGA or VGA). /E (or -E) sets the display to 43 lines on an EGA, or 50 lines on a VGA graphics card. /C (or -C) instructs SIMSTAT to use a compression procedure to reduce the size of the output file sent to disk. This option is useful for saving disk space when running SIMSTAT on a laptop, or on a computer with limited disk space. The compressed output file will take up to 75% less disk space than uncompressed. You can browse through the listing file from within SIMSTAT; however you cannot print or view this file outside the program. In order to do this, you must first uncompress the file with the EXPAND.EXE utility (see Appendix C). /X (or -X) suppress the introductory screen. You can use the SET command at DOS to include any of the above options automatically when you start SIMSTAT. For example, the following command: SET SIMSTAT=/M will cause the program to automatically run in black and white mode. Orientation through the screen ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When you call up SIMSTAT, the first screen you see is the introductory screen with product- version information. Pressing any key will make this screen disappear and bring you to the working screen (see figure 1) which is divided into three different parts: 1) The main menu at the top of the screen gives access to six pulldown menus from which commands can be invoked. 2) The status panel, located at the bottom of the screen, displays information about the program's operation. This panel is divided into three parts: The left side of the status panel displays special function keys that can be pressed. The middle part provides information about the destination of computer output (printer or disk). The right side of the status panel displays the data file name and the amount of memory available for analysis. 3) The central part of the screen is the output window, used to display the results of your analysis. Working with pulldown menus ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The following are basic instructions to help you navigate through the menu system: - To choose a menu command, type the first capital letter of the command name. You can also use the <right arrow> or <left arrow> keys to move to the command and press <Enter>. - Once in a main menu, select a sub-menu command by typing the first capital letter of the command name. You can also use the <Up> and <Dn> arrow keys highlight the command and press <Enter> to select your choice. Use the <right arrow> or <left arrow> keys to move from one pulldown menu to another. - You can press the <Home> key to go directly to the first command on the menu or the <End> key to go to the last command. - Press <Esc> to close pulldown menus. Function keys ~~~~~~~~~~~~~ Some function keys provide quick access to often used commands. In general, these keys can be activated from anywhere in the program. <F1> Press the <F1> key to obtain context-sensitive help. <F2> Pressing this key allows you to browse through the result of analysis. The scope of action of this key depends on whether or not the results are sent to disk. If the listing is saved on disk, you will be able to browse through the entire output file. If the disk log is off, this key allows you to browse only through the results of the most recent analysis. <F3> Pressing this key allows you to select dependent and independent variables (as shortcut for CHOOSE X-Y). <F4> Pressing this key allows you to call an external text editor in order to edit the output file. (See p.25 for instruction on how to install a text editor). <F6> Pressing this key makes SIMSTAT to pause between screens of output. <F7> Pressing this key toggles the printer log ON and OFF. <F8> Toggles disk log ON and OFF (as shortcut for I/O OPTIONS). <F9> Pressing this key sends a formfeed to the printer. Use this command to make sure that the next printing will begin at the top of a new page. This command works only if the printer log is ON. <Esc> Pressing the <Esc> key cancels any operation in progress (leaves a submenu or an options panel, aborts field editing, interrupts statistical computation, etc.). <F10> The <F10> key is often used to confirm the editing of a panel and to proceed with the chosen command. Options panels ~~~~~~~~~~~~~~ Some SIMSTAT commands in submenus are followed by three dots. These dots indicate that an options panel appears when you choose this command. These panels allow you to specify various options used to adjust the program's operation, to customize the analysis output, or to specify conditions to be fulfilled by an analysis. To navigate through the options panels use the following keys: <Tab>,<Dn> or <ENTER> move to the next field; <Shift-Tab> or <Up> move to the previous field. The action needed to edit the values of the various options depends on the type of input field. Options panels can contain three different types of input field: Data entry fields - (numeric or alphanumeric) Data entry fields are options where you must type a value using the keyboard. They are used to enter a string of characters, a number, a filename, etc.. When you are positioned on such a field, a blinking text-cursor appears. The following table lists the keys that can be used while editing a string field. Key Effect ------------- ----------------------------------------------- <right arrow> Moves the cursor onto the character to the right. <left arrow> Moves the cursor onto the character to the left. <Ctrl-left> Moves the cursor to the beginning of the next word. <Ctrl-right> Moves the cursor to the beginning of the previous word. <Del> Deletes the character on which the cursor is positioned. <Backspace> Deletes the character to the left of the cursor. <Home> Moves the cursor to the first character of the line. <End> Moves the cursor to the last character of the line. <Ctrl-K> Delete from cursor postion to the end of the line. <Ins> Pressing this key toggles between insert and overwrite mode. In insert mode, characters are inserted at the cursor position pushing existing text to the right of the cursor even further right. When in overwrite mode, characters at the cursor position are overwritten. A blinking box cursor is used to indicate that the insert mode is active, while the overwrite mode is identify by a single line cursor. <Esc> Aborts the editing process and restore the previous value. Boolean fields - This type of field can take only two values (e.g., Yes vs. No, One-tail vs. Two-tailed, etc.). When editing a boolean field, no cursor appears. Use the <spacebar> to toggle between the current and alternate values. You can also press the first letter of the boolean value (e.g., Y for Yes, or N for No) to choose it. Using this method immediately moves you to the next field. List fields - This type of field can take more than two values. They can be recognized by the symbol on the right side of the field when highlighted. By pressing the <left arrow> key, a list box appears. You can then use the <Up> and <Dn> arrows to highlight the proper choice and then press <Enter> to confirm it. After the values have been edited to suit your needs, you have to press the <F10> key to accept those values and proceed. If you want to leave the options panel, restore the previous values, and suspend the current operation, just press the <Esc> key. Using the mouse ~~~~~~~~~~~~~~~ The mouse can also be used to navigate through the menus; select and edit options; and activate some function keys. Only the left button is used by SIMSTAT. Here are some guidelines on the way to use the mouse. Menus ~~~~~ - To open a menu, point to the menu name and click the left button. - To select a submenu command, point to the option and click once. - To close a submenu, position the pointer outside the menu you want to close and click the left button. Options panels ~~~~~~~~~~~~~~ - To select a specific field in an options panel, position the mouse cursor on the field and click once. - To change the value of a boolean field, position the mouse cursor on the field and click once. If you are currently on another field, double-clicking on the boolean fields will achieve the same result: The first click will position the cursor on the boolean field while the second click will toggle its value. - To select a value in a list field, select the list field by clicking on it once, click again on it to bring up the list window, position the pointer on the value you want to choose, and click on it to confirm your choices. - To escape from the options panel and restore the previous values, click outside the panel. - To accept the current values and continue, click anywhere on the F10-to proceed expression. Function keys ~~~~~~~~~~~~~ Most function keys appearing on the status panel or on the border of windows can be activated with the mouse by simply clicking anywhere on the command expression. Getting help ~~~~~~~~~~~ No matter where you are in SIMSTAT, you can get more information about the task you're working on by pressing <F1>. This function key accesses SIMSTAT's context-sensitive help. When more that one page of information is available on your current task, a PgDn or PgUp message will appear at the bottom of the help window to tell you that there are other pages of information. Use the corresponding key to display those other pages. Pressing <F1> another time accesses more general help. Press <ESC> to leave HELP and return to your previous location. Tutorial - Performing statistical analysis ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The following section provides step-by-step instructions for computing descriptive statistics and regression analysis on a sample data file. The data is from an imaginary study about various factors influencing children's aggressive behavior during school recreational activities. This tutorial uses data stored in the dBase III file named SAMPLE.DBF that come with your program disk. Step 1 - Opening a data file for analysis The first step to performing a statistical analysis is to open a data file that you want to analyse. After calling up SIMSTAT, select the OPEN FILE command from the FILE menu. This command pulls down a window that lists all valid files and subdirectories (see Figure 2). Using the arrow keys, position the highlighted bar on the SAMPLE.DBF (dBase) file then press <Enter>. This opens the highlighted file. If the file is not in the default directory, you can navigate through directories by highlighting a subdirectory and pressing <Enter> to change to that directory. To open a data file on a different drive, press <F3> and select the appropriate drive letter. If you want to perform the same operation using the mouse, click with the left button on the FILE menu, then click on the OPEN FILE submenu. To open the SAMPLE.DBF file, position the mouse pointer on the file name and click twice with the left button. If the file is not in the default directory, you can navigate through directories by pointing to a subdirectory and double-clicking with the left button to change to that directory. When a file is successfully opened, its name appears at the right end of the status panel at the bottom of the screen. The output screen also gives information about the active file, including its type, the number of variables and the number of cases. Step 2 - Assigning variables The next step is to choose the variable(s) on which you will perform the analysis. Select the CHOOSE X-Y command from the VARIABLE menu. The program now displays, in a window, the list of all variables in the active file (see Figure 3). The first variable is highlighted. Below the variable list, an information window gives more detailed information about the highlighted variable. Use the direction keys to move around the list and press either the X, Y, or Z key to specify whether the variable is to be treated as an independent variable, as a dependent variable, or as both. For our example, highlight the AGE variable (age of the child) and press X to select it as an independent variable. Notice that a small x appears next to the variable name in the variable list. If you select the wrong variable, simply move back to that variable and press either the <DEL> key or the <SPACEBAR> to unselect it. Next, move to the variable name HOURSTV (number of hours spent watching TV programs with violent content) using the arrow keys, and press X to select this variable as another independent variable. Using the Y key, select AGRESS (number of agressive behaviors observed) as a dependent variable. To select a variable with the mouse, click on the variable you want to choose, then move the mouse pointer to the status panel. Position the mouse pointer over the definition you want to choose and click once with the left button. To activate the selection of variables and go back to the main menu, press <F10>. If you want to cancel the operation and restore the previous variable's definition, just press <Esc>. Step 3 - Performing frequencies analysis All the commands for statistical analyses are grouped in the four right-most menus. We will now perform a frequency analysis on the variables we have chosen. Select FREQUENCIES from the DESCRIBE menu. An options panel appears on the screen. Using this panel, we will instruct the program to print a barchart, descriptive statistics, and a frequency table sorted by value. When the options panel is opened, the TABLE option is highlighted. This option is a boolean value that takes only two values: Yes or No. You can toggle this value by pressing the space bar. You can also type Y for yes and automatically move to the next field. Using the proper keys, set the different options to the following values: Sort by: Value Descriptive: Yes Percentiles: No Percentage: 90 Bar chart: Text Pie chart: No Pareto: No Box-&-whiskers: Text Cumul. chart: No Histogram: Text After selecting the options needed, you have to activate them and tell SIMSTAT to perform the analysis by pressing the <F10> key, or by clicking on the <F10> TO PROCEED statement at the lower-right corner of the panel. SIMSTAT will calculate the necessary statistics and display the output on your screen. Step 4 - Viewing the results As the results are displayed on screen, the first portion of it may scroll out of sight at the top of the screen so that only the last portion of the results remain visible. To browse through the entire results press the <F2> key. This command give you access to the BROWSE mode. To scroll backward through your results file, press the <PgUp> key. Use the <PgDn> key to move forward through the listing. The <Home> and the <End> keys can also be used to move to the beginning and to the end of the file. For finer movements, use the <Up> and <Dn> key. You can also scroll horizontally by using the <left arrow> and <right arrow> keys. Press <Esc> to leave the BROWSE mode and return to the main program. Step 5 - Selecting a subset of cases For our second analysis, we will perform a regression analysis using the previously selected variables. However, we will restrict the analysis to the male subjects. To select this subgroup, choose the SELECTION command from the VARIABLES menu. This command displays a status panel that includes two fields. The highlighted field allows you to specify a condition that must be met in order to include the case in the analysis. The sex of the child has been stored in a numeric variable named SEX using 1 to designate boys and 2 for girls. To select the boys for the next analysis, type the following condition: SEX = 1 Then press <enter> to go to the next field. In order for the program to apply the specified selection, the ACTIVATE SELECTION option needs to be set to Yes. If this field's value is set to No, SIMSTAT will hold the condition in memory without using it. Press <F10> to proceed. Step 6 - Performing regression analysis Choose the REGRESSION command from the COMPARE menu. An options panel appears and the first option, TYPE, is highlighted. Note the symbol at the right end of this option. This arrow indicates that a list of choices is available. To examine the choices available under this field, press the <right arrow> key on the keyboard. SIMSTAT offers eight different types of regression. For this example, select LINEAR by highlighting this choice and pressing <Enter>. The cursor is now positioned on the DIRECTION option that allows you to specify whether the significance test should be 1 or 2-tailed. Select a 2-tailed test. To obtain a scatterplot that will allow you to visualize the relation between the dependent and independent variables, set the SCATTERPLOT option to Text (for a scatterplot in ASCII characters) or Graphic (for an high resolution graphic). At the CONF. INTERVAL option, edit the numeric field to 90 to obtain a 90% confidence interval on beta weights. Set the RESIDUAL PLOT to No and the STANDARDIZE RESIDUAL to None. When you press <F10>, SIMSTAT will calculate two separate linear regression equations with AGRESS as the dependent variable and AGE and HOURSTV as predictors. You can now press the <F2> key to browse through the results. Creating a hard-copy of analysis results ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ By default, analysis results are not preserved. Once you're out of the program, they cannot be seen, edited or used. SIMSTAT provides two different means for generating hard copy output of analysis results for later use. They could be saved on disk or sent to the printer. This section introduces you to the operations necessary to producing a hard copy on disk and on the printer. Saving the results on disk The last analysis results you obtained are normally sent to a temporarily file. This file is automatically erased when you exit the program. If you want to keep the results in a text file, you have to tell SIMSTAT to save those results in a listing file. One way to do this is to choose the I/O OPTIONS command from the FILE menu and to set the ON DISK option to YES. By default SIMSTAT saves the listing in a file called SIMSTAT.LIS. You can change the default filename used by the program by editing the value under the FILENAME field. You can also toggle the disk-capture ON and OFF at any time by pressing the <F6> key. If the disk-capture is ON, the following result will be appended to the listing file. If the disk-capture is OFF, they won't. In order to inform you of the state of disk-capture, the status line will show the word disk when the disk log is ON. Sending the results to the printer ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Before using the print command, be sure that a printer is connected to the computer, turned on, and supplied with paper. Also, make sure that the program is properly configured to work with your printer. The program's initial setting allows printing on an IBM compatible dot-matrix printer connected to the LPT1 printer port. (refer to the I/O OPTIONS command at page 35 to adjust the printer setup). If you want your results sent to the printer, one way to do it is to indicate it in the I/O OPTIONS command of the FILE menu. However, doing this does not print results already on the screen. You can also toggle the printer ON and OFF at any time by pressing the <F7> key. The status line will keep you informed of the printer status by displaying the word Printer on the status panel when the printer log is ON.