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Type: HR, Report if not a HR topic
Appreciate your help Shivprasad and Sudarshan,
But "Force choice method" is one which forced the appraiser to rate the apraisee.... is it...? plz clear me, in case m wrong. There are some ratings like 10%, 30%, 50% etc etc, which the appraiser has to select nd rate the appraisee. so just putting this percentage on curve, is it called Bell Curve....???
Waiting for the clarification..!! In case if you have any material for this, post it here only sothat every one will get benefit.
Priyanka
How to Create a Bell Curve Chart for MSOFFICE 97-2000
A bell curve is a plot of normal distribution of a given data set. This article...
A bell curve is a plot of normal distribution of a given data set. This article describes how you can create a chart of a bell curve in Microsoft Excel.
In the following example you can create a bell curve of data generated by Excel...
In the following example you can create a bell curve of data generated by Excel using the Random Number Generation tool in the Analysis Tool Pak. After Microsoft Excel generates a set of random numbers, you can create a histogram using those random numbers and the Histogram tool from the Analysis ToolPak. From the histogram, you can create a chart to represent a bell curve.
To create a sample bell curve, follow these steps:
1. Start Excel.
2. Enter the following column headings in a new worksheet:
3. A1:Original B1:Average C1:Bin D1:Random E1:Histogram G1:Histogram
4. Enter the following data in the same worksheet:
5. A2: 23 B2:
6. A3: 25 B3: STDEV
7. A4: 12 B4:
8. A5: 24
9. A6: 27
10. A7: 57
11. A8: 45
12. A9: 19
13. Enter the following formulas in the same worksheet:
14. B2: =AVERAGE(A2:A9)
15. B3:
16. B4: =STDEV(A2:A9)
These formulas will generate the average (mean) and standard deviation of the original data, respectively.
Enter the following formulas to generate the bin range for the histogram:
17. C2: =$B$2-3*$B4
This generates the lower limit of the bin range. This number represents three standard deviations less than the average.
C3: =C2+$B$4
This formula adds one standard deviation to the number calculated in the cell above.
18. Select Cell C3, grab the fill handle, and then fill the formula down from cell C3 to cell C8.
19. To generate the random data that will form the basis for the bell curve, follow these steps:
0. On the Tools menu, click Data Analysis.
1. In the Analysis Tools box, click Random Number Generation, and then click OK.
2. In the Number of Variables box, type 1.
3. In the Number of Random Numbers box, type 2000.
NOTE: Varying this number will increase or decrease the accuracy of the bell curve.
4. In the Distribution box, select Normal.
5. In the Parameters pane, enter the number calculated in cell B2 (29 in the example) in the Mean box.
6. In the Standard Deviation box enter the number calculated in cell B4 (14.68722).
7. Leave the Random Seed box blank.
8. In the Output Options pane, click Output Range.
9. Type D2 in the Output Range box.
This will generate 2,000 random numbers that fit in a normal distribution.
10. Click OK.
20. To create a histogram for the random data, follow these steps:
0. On the Tools menu, click Data Analysis.
1. In the Analysis Tools box, select Histogram, and then click OK.
2. In the Input Range box, type D2:D2001.
3. In the Bin Range box, type C2:C8.
4. In the Output Options pane, click Output Range.
5. Type E2 in the Output Range box.
6. Click OK.
21. To create a histogram for the original data, follow these steps:
0. On the Tools menu, click Data Analysis.
1. Click Histogram, and then click OK.
2. In the Input Range box, type A2:A9.
3. In the Bin Range box, type C2:C8.
4. In the Output Options pane, click Output Range.
5. Type G2 in the Output Range box.
6. Click OK.
22. Create labels for the legend in the chart by entering the following:
23. E14: =G1&"-"&G2
24. E15: =E1&"-"&F2
25. E16: =G1&"-"&H2
26. Select the range of cells, E2:H10, on the worksheet.
27. On the Insert menu, click Chart.
28. Under Chart type, click XY (Scatter).
29. Under Chart sub-type, in the middle row, click the chart on the right.
NOTE: Just below these 5 sub-types, the description will say "Scatter with data points connected by smoothed lines without markers."
30. Click Next.
31. Click the Series tab.
32. In the Name box, delete the cell reference, and then select cell E15.
33. In the X Values box, delete the range reference, and then select the range E3:E10.
34. In the Y Values box, delete the range reference, and then select the range F3:F10.
35. Click Add to add another series.
36. Click the Name box, and then select cell E14.
37. Click the X Values box, and then select the range E3:E10.
38. In the Y Values box, delete the value that's there, and then select the range G3:G10.
39. Click Add to add another series.
40. Click the Name box, and then select cell E16.
41. Click the X Values box, and then select the range E3:E10.
42. Click the Y Values box, delete the value that's there, and then select the range H3:H10.
43. Click Finish.
The chart will have two curved series and a flat series along the x-axis.
44. Double-click the second series; it should be labeled "- Bin" in the legend.
45. In the Format Data Series dialog box, click the Axis tab.
46. Click Secondary Axis, and then click OK.
You now have a chart that compares a given data set to a bell curve.
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Bell Curve
Type: HR, Report if not a HR topic
Posted 01-04-2009Reply
Friends,
can some one help with information on Bell Curve.....
Hi Archana,
A bell curve is a theoretical dsitribution of scores across a given population. Applied to PMS, this means that the performance of the majority of a given population will tend to gravitate towards the center i.e., average while the extremes would comprise of either the poor performers or excellent ones. This simply means that you can't have 100% stars in a team; there has to be the so-so (average) guys and low performers. The curve is mostly used as a control mechanism.
Source : http://www.chrmglobal.com
I really want to explain bell curve with a graph but not able get an image of it in the net...Anyway I think u can visualise...
Sudarshan
sudarmr1978@gmail.com
A bell curve is a theoretical dsitribution of scores across a given population. Applied to PMS, this means that the performance of the majority of a given population will tend to gravitate towards the center i.e., average while the extremes would comprise of either the poor performers or excellent ones. This simply means that you can't have 100% stars in a team; there has to be the so-so (average) guys and low performers. The curve is mostly used as a control mechanism.
Source : http://www.chrmglobal.com
I really want to explain bell curve with a graph but not able get an image of it in the net...Anyway I think u can visualise...
Sudarshan
sudarmr1978@gmail.com
Hi,
As above mentioning note. its distribution. In Practice its called Forced Ranking Method. Initially practiced by GE when they are in the Growth face. Still they do the same practice. In GE its called Vitality curve.
This method includes comparative ratings and MBO-Management by Objectives. Its talk relative value of contribution to the Organization Goals and Competencies’.
How you form a Bell Curve is a big exercise’s hat require a clarity in Organization goals and creating a clear quantitative Goals at Organization, Team and Individual levels.
If you want more information, please write to me shivaprasad.tadi@gmail.com. Because its vast subject.
Shiva
As above mentioning note. its distribution. In Practice its called Forced Ranking Method. Initially practiced by GE when they are in the Growth face. Still they do the same practice. In GE its called Vitality curve.
This method includes comparative ratings and MBO-Management by Objectives. Its talk relative value of contribution to the Organization Goals and Competencies’.
How you form a Bell Curve is a big exercise’s hat require a clarity in Organization goals and creating a clear quantitative Goals at Organization, Team and Individual levels.
If you want more information, please write to me shivaprasad.tadi@gmail.com. Because its vast subject.
Shiva
Hi,
As above mentioning note. its distribution. In Practice its called Forced... See Shivaprasad's complete reply
As above mentioning note. its distribution. In Practice its called Forced... See Shivaprasad's complete reply
Appreciate your help Shivprasad and Sudarshan,
But "Force choice method" is one which forced the appraiser to rate the apraisee.... is it...? plz clear me, in case m wrong. There are some ratings like 10%, 30%, 50% etc etc, which the appraiser has to select nd rate the appraisee. so just putting this percentage on curve, is it called Bell Curve....???
Waiting for the clarification..!! In case if you have any material for this, post it here only sothat every one will get benefit.
Priyanka
A bell curve is a graph of a NORMAL DISTRIBUTION of virtually any trait within a population. The classic example is plotting heights within a class of children. (I can't believe you never did this at school). Starting at the bottom left corner we see the small number of very short children, moving to the middle of the graph the curve rises as the majority of the class is of average height (average for that group) and the right hand tail of the graph shows the small number of particularly tall children. The curve resembles a classic bell shape.
The larger the sample of examples the more nearly the curve fits to the classic bell shape. If you plotted the entire human race the curve would be very smooth indeed. What you can do for heights you can do for anything else, including IQ scores, weight, age of death, income and propensity to commit criminal acts. Any population that has diversity within it will yield a bell curve. Sometimes it will be skewed to the left or right, sometimes it will be very sharply defined around a median figure other times the distribution will be very broad.
Populations of anything in the natural world usually fall into a normal distribution pattern, with most values falling in the middle of the range and smaller numbers to either side.
If you plot the income curve of a capitalist economy it will have a left skewed plot, the majority of people will be earning less than the mean (average) income, the mean will be pulled out strongly to the right by a small handful of the very rich. From the origin the curve will rise almost sheer because of the large number of people who earn next to nothing, then it will reach a peak just past the “minimum wage” level and then tail off slowly reflecting the smaller numbers of people who earn up to five times the minimum wage level. Then it drops off rapidly to a near horizontal trace reflecting the fact that less than 1% of the population earn obscene levels of income. If you ever hear anybody use the phrase “how the other half live” about the rich please correct them; they might own the other half of the world's resources but they are less than 1% of the human race.
Source - http://www.mwillett.org/bell.htm
Ritesh
The larger the sample of examples the more nearly the curve fits to the classic bell shape. If you plotted the entire human race the curve would be very smooth indeed. What you can do for heights you can do for anything else, including IQ scores, weight, age of death, income and propensity to commit criminal acts. Any population that has diversity within it will yield a bell curve. Sometimes it will be skewed to the left or right, sometimes it will be very sharply defined around a median figure other times the distribution will be very broad.
Populations of anything in the natural world usually fall into a normal distribution pattern, with most values falling in the middle of the range and smaller numbers to either side.
If you plot the income curve of a capitalist economy it will have a left skewed plot, the majority of people will be earning less than the mean (average) income, the mean will be pulled out strongly to the right by a small handful of the very rich. From the origin the curve will rise almost sheer because of the large number of people who earn next to nothing, then it will reach a peak just past the “minimum wage” level and then tail off slowly reflecting the smaller numbers of people who earn up to five times the minimum wage level. Then it drops off rapidly to a near horizontal trace reflecting the fact that less than 1% of the population earn obscene levels of income. If you ever hear anybody use the phrase “how the other half live” about the rich please correct them; they might own the other half of the world's resources but they are less than 1% of the human race.
Source - http://www.mwillett.org/bell.htm
Ritesh
How to Create a Bell Curve Chart for MSOFFICE 97-2000
A bell curve is a plot of normal distribution of a given data set. This article...
A bell curve is a plot of normal distribution of a given data set. This article describes how you can create a chart of a bell curve in Microsoft Excel.
In the following example you can create a bell curve of data generated by Excel...
In the following example you can create a bell curve of data generated by Excel using the Random Number Generation tool in the Analysis Tool Pak. After Microsoft Excel generates a set of random numbers, you can create a histogram using those random numbers and the Histogram tool from the Analysis ToolPak. From the histogram, you can create a chart to represent a bell curve.
To create a sample bell curve, follow these steps:
1. Start Excel.
2. Enter the following column headings in a new worksheet:
3. A1:Original B1:Average C1:Bin D1:Random E1:Histogram G1:Histogram
4. Enter the following data in the same worksheet:
5. A2: 23 B2:
6. A3: 25 B3: STDEV
7. A4: 12 B4:
8. A5: 24
9. A6: 27
10. A7: 57
11. A8: 45
12. A9: 19
13. Enter the following formulas in the same worksheet:
14. B2: =AVERAGE(A2:A9)
15. B3:
16. B4: =STDEV(A2:A9)
These formulas will generate the average (mean) and standard deviation of the original data, respectively.
Enter the following formulas to generate the bin range for the histogram:
17. C2: =$B$2-3*$B4
This generates the lower limit of the bin range. This number represents three standard deviations less than the average.
C3: =C2+$B$4
This formula adds one standard deviation to the number calculated in the cell above.
18. Select Cell C3, grab the fill handle, and then fill the formula down from cell C3 to cell C8.
19. To generate the random data that will form the basis for the bell curve, follow these steps:
0. On the Tools menu, click Data Analysis.
1. In the Analysis Tools box, click Random Number Generation, and then click OK.
2. In the Number of Variables box, type 1.
3. In the Number of Random Numbers box, type 2000.
NOTE: Varying this number will increase or decrease the accuracy of the bell curve.
4. In the Distribution box, select Normal.
5. In the Parameters pane, enter the number calculated in cell B2 (29 in the example) in the Mean box.
6. In the Standard Deviation box enter the number calculated in cell B4 (14.68722).
7. Leave the Random Seed box blank.
8. In the Output Options pane, click Output Range.
9. Type D2 in the Output Range box.
This will generate 2,000 random numbers that fit in a normal distribution.
10. Click OK.
20. To create a histogram for the random data, follow these steps:
0. On the Tools menu, click Data Analysis.
1. In the Analysis Tools box, select Histogram, and then click OK.
2. In the Input Range box, type D2:D2001.
3. In the Bin Range box, type C2:C8.
4. In the Output Options pane, click Output Range.
5. Type E2 in the Output Range box.
6. Click OK.
21. To create a histogram for the original data, follow these steps:
0. On the Tools menu, click Data Analysis.
1. Click Histogram, and then click OK.
2. In the Input Range box, type A2:A9.
3. In the Bin Range box, type C2:C8.
4. In the Output Options pane, click Output Range.
5. Type G2 in the Output Range box.
6. Click OK.
22. Create labels for the legend in the chart by entering the following:
23. E14: =G1&"-"&G2
24. E15: =E1&"-"&F2
25. E16: =G1&"-"&H2
26. Select the range of cells, E2:H10, on the worksheet.
27. On the Insert menu, click Chart.
28. Under Chart type, click XY (Scatter).
29. Under Chart sub-type, in the middle row, click the chart on the right.
NOTE: Just below these 5 sub-types, the description will say "Scatter with data points connected by smoothed lines without markers."
30. Click Next.
31. Click the Series tab.
32. In the Name box, delete the cell reference, and then select cell E15.
33. In the X Values box, delete the range reference, and then select the range E3:E10.
34. In the Y Values box, delete the range reference, and then select the range F3:F10.
35. Click Add to add another series.
36. Click the Name box, and then select cell E14.
37. Click the X Values box, and then select the range E3:E10.
38. In the Y Values box, delete the value that's there, and then select the range G3:G10.
39. Click Add to add another series.
40. Click the Name box, and then select cell E16.
41. Click the X Values box, and then select the range E3:E10.
42. Click the Y Values box, delete the value that's there, and then select the range H3:H10.
43. Click Finish.
The chart will have two curved series and a flat series along the x-axis.
44. Double-click the second series; it should be labeled "- Bin" in the legend.
45. In the Format Data Series dialog box, click the Axis tab.
46. Click Secondary Axis, and then click OK.
You now have a chart that compares a given data set to a bell curve.
Bell curve is also called Gaussian curve and represents the standard normal distribution. Ritesh detailed it very well.
You can see its shape and understand how it is calculated on:
http://www.daviddarling.info/images/Bell_curve.jpg
http://psy.ucsd.edu/~rdbeer/images/GaussCurve.jpg
You can see its shape and understand how it is calculated on:
http://www.daviddarling.info/images/Bell_curve.jpg
http://psy.ucsd.edu/~rdbeer/images/GaussCurve.jpg
Hi all,
Good postings. Thanks John for your great effort in explaining the process of making in excel sheet for Bell Curve
Indeed Bell Curve is a vital point in a Performance Management System. But effectiveness of the system depends more on Pre and Post Process of the Appraisal that includes
1. Clear Organizational Goals and Clarity in Value Systems & Communicating the same across the Organization
2. Define clear KRA at Various Level in the Organization - Organization, Team and Individual
3. Define clear Performance Indicators to each KRA'
4. Good Performance Monitoring and Coaching Skills in Appraisers
5. Appraisers should have good Skills Performance Appraisal Review and Giving Feedback
6.Good Performance Recognition Process
Above few are i feel fundamental processes have to be strong for an effective Performance Management
Shiva
Good postings. Thanks John for your great effort in explaining the process of making in excel sheet for Bell Curve
Indeed Bell Curve is a vital point in a Performance Management System. But effectiveness of the system depends more on Pre and Post Process of the Appraisal that includes
1. Clear Organizational Goals and Clarity in Value Systems & Communicating the same across the Organization
2. Define clear KRA at Various Level in the Organization - Organization, Team and Individual
3. Define clear Performance Indicators to each KRA'
4. Good Performance Monitoring and Coaching Skills in Appraisers
5. Appraisers should have good Skills Performance Appraisal Review and Giving Feedback
6.Good Performance Recognition Process
Above few are i feel fundamental processes have to be strong for an effective Performance Management
Shiva
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