Difference between revisions of "Improvement score"
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{{MitoPedia | |||
|abbr=''RIS'' | |||
|description=The relative improvement score, ''RIS'', provides a measure of improvement of a trait from a value measured at baseline, ''B'', to a value measured after treatment, ''T'', expressing the total improvement, ''T-B'', in relation to the theoretical scope of improvement and the level of the trait observed at baseline. '''RIS'' incorporates the concept of diminishing returns and consideres maintaining a high value of a trait as an improvement relative to the potential loss. | |||
}} | |||
{{MitoPedia concepts}} | |||
{{MitoPedia methods}} | |||
{{MitoPedia O2k and high-resolution respirometry | |||
|mitopedia O2k and high-resolution respirometry=Oroboros QM | |||
}} | |||
{{MitoPedia topics | |||
|mitopedia topic=EAGLE | |||
}} | |||
৳ | |||
== What is positive and negative improvement? == | == What is positive and negative improvement? == | ||
:::: | :::: A '''relative improvement score''', ''RIS'', requires measurements at baseline, ''B'', and after treatment, ''T'', of a trait that increases as a positive measure of improvement (''B''>0 and ''T''>0). | ||
:::::# ''T-B'' | :::: The absolute improvement is the difference ''T-B'' and distinguishes three conditions: | ||
:::::# ''T-B'' | :::::# ''T-B'' > 0. There is positive improvement, and ''RIS'' > 0. | ||
:::::# ''T-B'' | :::::# ''T-B'' < 0. There is negative improvement, and ''RIS'' < 0. | ||
:::::# ''T-B'' = 0. There is no absolute change. The value of ''RIS'' is zero if the lowest baseline score, ''B''=1, has not improved. In contrast, the relative improvement should be considered as a positive result, if a high value of ''B'' is maintained. ''Improvement'' is then considered relative to a potential decline of ''T'' compared to ''B''. | |||
== When does improvement become more difficult to achieve? == | == 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, ''B''<sub>max</sub> = ''T''<sub>max</sub>, the scope for absolute improvement diminishes, and the same small absolute improvement becomes more difficult to achieve. Β | :::: 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, ''B''<sub>max</sub> = ''T''<sub>max</sub>, the scope for absolute improvement diminishes, and the same small absolute improvement becomes more difficult to achieve. Even maintaining rather than loosing ''B''<sub>max</sub> is a significant achievement, which is considered as a positive ''RIS''. | ||
== How does the improvement score behave? == | == How does the relative improvement score behave? == | ||
::::# If ''T>B'', ''T-B'' is positive; there is a positive ''RIS''. | |||
::::# If ''T>B'', ''T-B'' is positive; there is a positive '' | ::::# If ''T<B'', ''T-B'' is negative; there is a negative ''RIS''. | ||
::::# If ''T<B'', ''T-B'' is negative; there is a negative '' | ::::# 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 ''RIS'' at higher values of ''B'' and ''T''. | ||
::::# 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 '' | ::::# The relationship between ''T-B'' and ''RIS'' should have the same proportionality for positive and negative ''T-B'' values, ''i.e.'', if the highest ''RIS''=9, then the worst is -9. | ||
::::# The relationship between ''T-B'' and '' | ::::# Positive and zero values of ''T-B'' are treated by an equation that is different from the equation for negative values of ''T-B''. | ||
::::# Positive and | ::::# If ''B''=''T''<sub>min</sub>=1, ''T-B''=0, then ''RIS''=0. | ||
::::# If ''B''=''T''>1, ''T-B''=0, then ''RIS'' has a positive value that increases with increasing ''B''. | |||
::::# If ''B''=''T''<sub>max</sub>, ''T-B''=0, then ''RIS'' has a relatively high positive value. | |||
:::: These criteria are met by two equations | :::: These criteria are met by application of two equations: | ||
Β <big>Positive improvement, ''T>B''</big> | Β <big>Positive improvement, ''T>B'', and maintenance of the baseline value, ''T=B''</big> | ||
:::::::: '' | :::::::: Eq.(1) | ||
:::::::::::::::: ''RIS'' = (''T*T''-''B'')/(''T''+''B'') | |||
Β <big>Negative improvement, ''T<B''</big> | Β <big>Negative improvement, ''T<B''</big> | ||
:::::::: '' | :::::::: Eq.(2) | ||
:::::::::::::::: ''RIS'' = (''T''-''B*B'')/(''T''+''B'') | |||
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== Alternative models == | |||
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=== No improvement at ''T''=''B''? === | |||
Β | |||
::::: ''T=B'' indicates no absolute improvement. It may be considered to assign a zero value to the relative improvement score. This is problematic, if the baseline score is at a maximum value, leaving no scope for absolute improvement, and the absolute improvement score equals zero. The same zero value would be given for maintaining a minimum score ''B''<sub>min</sub>, when the scope for improvement is actually very high. This problem is solved by applying Eq.(1) to ''T=B''. | |||
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=== A quick comparison === | |||
Β | |||
:::: The resulting Bioblast '''Relative Improvement Score''', ''RIS'', represents a significant improvement in comparison to previous concepts. | |||
::::* Compare: | |||
::::::Β» https://www.nngroup.com/articles/improvement-score/ |
Latest revision as of 05:14, 19 July 2022
Description
The relative improvement score, RIS, provides a measure of improvement of a trait from a value measured at baseline, B, to a value measured after treatment, T, expressing the total improvement, T-B, in relation to the theoretical scope of improvement and the level of the trait observed at baseline. 'RIS incorporates the concept of diminishing returns and consideres maintaining a high value of a trait as an improvement relative to the potential loss.
Abbreviation: RIS
MitoPedia O2k and high-resolution respirometry:
Oroboros QM
MitoPedia topics:
EAGLE
৳
What is positive and negative improvement?
- A relative improvement score, RIS, requires measurements at baseline, B, and after treatment, T, of a trait that increases as a positive measure of improvement (B>0 and T>0).
- The absolute improvement is the difference T-B and distinguishes three conditions:
- T-B > 0. There is positive improvement, and RIS > 0.
- T-B < 0. There is negative improvement, and RIS < 0.
- T-B = 0. There is no absolute change. The value of RIS is zero if the lowest baseline score, B=1, has not improved. In contrast, the relative improvement should be considered as a positive result, if a high value of B is maintained. Improvement is then considered relative to a potential decline of T compared to B.
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. Even maintaining rather than loosing Bmax is a significant achievement, which is considered as a positive RIS.
How does the relative improvement score behave?
- If T>B, T-B is positive; there is a positive RIS.
- If T<B, T-B is negative; there is a negative RIS.
- 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 RIS at higher values of B and T.
- The relationship between T-B and RIS should have the same proportionality for positive and negative T-B values, i.e., if the highest RIS=9, then the worst is -9.
- Positive and zero values of T-B are treated by an equation that is different from the equation for negative values of T-B.
- If B=Tmin=1, T-B=0, then RIS=0.
- If B=T>1, T-B=0, then RIS has a positive value that increases with increasing B.
- If B=Tmax, T-B=0, then RIS has a relatively high positive value.
- These criteria are met by application of two equations:
Positive improvement, T>B, and maintenance of the baseline value, T=B
- Eq.(1)
- RIS = (T*T-B)/(T+B)
- Eq.(1)
Negative improvement, T<B
- Eq.(2)
- RIS = (T-B*B)/(T+B)
- Eq.(2)
Alternative models
No improvement at T=B?
- T=B indicates no absolute improvement. It may be considered to assign a zero value to the relative improvement score. This is problematic, if the baseline score is at a maximum value, leaving no scope for absolute improvement, and the absolute improvement score equals zero. The same zero value would be given for maintaining a minimum score Bmin, when the scope for improvement is actually very high. This problem is solved by applying Eq.(1) to T=B.
A quick comparison
- The resulting Bioblast Relative Improvement Score, RIS, represents a significant improvement in comparison to previous concepts.
- Compare:
- The resulting Bioblast Relative Improvement Score, RIS, represents a significant improvement in comparison to previous concepts.