Difference between revisions of "Improvement score"
From Bioblast
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:::::::: ''IS'' = (''T''-''B*B'')/(''T''+''B'') | :::::::: ''IS'' = (''T''-''B*B'')/(''T''+''B'') | ||
:::: The '''Bioblast-Improvement Score''' presented here represents a significant improvement in comparison to previous concepts. | |||
:::::: Compare: https://www.nngroup.com/articles/improvement-score/ |
Revision as of 20:23, 29 April 2018
What is positive and negative improvement?
- An improvement score, IS, requires measurements at baseline, B, and after treatment, T, of a trait that increases as a positive measure of improvement. The difference T-B distinguishes three conditions:
- T-B = 0. There is no improvement, and IS = 0.
- T-B > 0. There is positive improvement, and IS > 0.
- T-B < 0. There is negative improvement, and IS < 0.
- An improvement score, IS, requires measurements at baseline, B, and after treatment, T, of a trait that increases as a positive measure of improvement. The difference T-B distinguishes three conditions:
When does improvement become more difficult to achieve?
- The same absolute improvement, T-B, is more easily achieved when the trait has a low value at baseline (B is low). As B approaches the theoretical maximum, Bmax = Tmax, the scope for absolute improvement diminishes, and the same small absolute improvement becomes more difficult to achieve.
How does the improvement score behave?
- If T=B, T-B=0, then IS=0
- If T>B, T-B is positive; there is a positive IS.
- If T<B, T-B is negative; there is a negative IS.
- A positive T-B value is more difficult to achieve, the higher the initial value of B. Therefore, the same value of T-B should have a higher IS at higher values of B and T.
- The relationship between T-B and IS should have the same proportionality for positive and negative T-B values, i.e., if the highest IS=1, then the worst is -1.
- Positive and negative values of T-B are treated by different equations.
- These criteria are met by two equations, and none of the equations is applied to T=B, when IS=0:
Positive improvement, T>B
- IS = (T*T-B)/(T+B)
Negative improvement, T<B
- IS = (T-B*B)/(T+B)
- The Bioblast-Improvement Score presented here represents a significant improvement in comparison to previous concepts.