Guru Wax Report - Double counting?

[Onehole]

Just received my Guru Wax Report and it looks like (to me) they are double counting.



They calculate a a grade point average as a function of:



40% Performance

30% Durability

20% Ease of Use

10% Availability



However Performance is the average of the subjective weekly performance (how it looks) scores over an 8 week period.



So the performance scores inherently factor in durability in the first place.



Interestingly P21S:



* Rated as good or better looking for 5 of the 8 weeks (better 1-3, equal 4-5),

* Rated just as easy to use as Zaino

* Better availability



Had a GPA well below Zaino? Did I miss something?



P21S ended with a B+ for performance (same as Zaino) because durability fell off (a little) in week 6 and collapsed in week 8, after a snow and ice storm in week 7 (where they could not do any measurements).



Now Zaino is a much more durable product, but it seems it has benefited twice in the overall GPA because of durability. Durability is scored seperatly and then again factored into the overall performance score. Again it seems like double counting to me.



Overall the report looks great, but this final score thing looks inaccurate.

[imported_BretFraz]

This is something you should PM GeekySteve about and ask directly. There are several threads in the archives discussing The Wax Test so consider reading those too.

[Steve @ Guru]

Sorry I was away for so long - I just got to NYC and am at the W hotel near Times Square... nice place! :)



Anyway, I get this question constantly, but people don`t realize that there is no "durability" grade assigned in the Performance (40%) grade charts. We only comment on beading quality and characteristics. The durability grade (30%) that you see in the thumbnails is the effective durability grade as reported from the chart - there`s no "double counting it."



Granted, there are some other mistakes in the report, but no one`s perfect and we openly admit to our mistakes when they`re made. We also try to improve the process to prevent similar errors... but in this case, there was no double counting. I put the beading info in the grade chart because it was the only place it would fit.



Edit:

And, as I always say, the Wax Test is not the Holy Grail of product testing. Your results may vary. It`s simply a comparison between products tested in a similar environment... If you`re happy with the products you`re using, please keep using them.

[Onehole]

Sorry I must be missing something?



P21S`s overall performance was a B+. Its started as A- (week 1) and finished as C+ (week 8). Therefore its overall grade was B+. Clearly because of its lack of durability, its Overall Performance rating was lower.



You then seperately scored Durability.



You then took 40% of Overall Performance + 30% Durability + 20% Ease of Use and 10% Availability to give an overal GPA.



Unless I have missed something, durability is clearly a factor in the Overall Performance score and the Durability score.



Did I miss something?

[Steve @ Guru]

Can you show me where durability was given a grade as part of overall performance grades?



There is no grade assigned to durability in the performance chart - the bead sizes and description are only listed for reference... I can assure you that we didn`t double score durability... I`ve double checked the report just to be sure.



I think you`re reading too much into it. :)

[Onehole]

Originally posted by geekysteve

Can you show me where durability was given a grade as part of overall performance grades?



Instead of just giving a single initial grade for performance you chose to evaluate the look of the wax every week for 8 weeks. The purpose of that was no doubt to access the staying power or durability of the wax. Therefore durability is factored into the 8 week average performance score.



I have explained this point 3 times now and 3 times you have ignored it. :(

[Steve @ Guru]

Again, I think you`re reading too much into it. Obviously as a wax wears away, the optics will suffer. However, to say that we double counted the durability as a result is highly inaccurate. How upset would folks be if after 8 weeks we just assigned a single grade of "whatever" for a product`s performance?



I think most folks would agree that they`d rather see how the things like depth, clarity, reflectivity, shine, gloss, etc. fared week-by-week because then they can determine for themselves which waxes suit their needs best. Some folks want a wax that looks great for a week, others expect the looks to remain constant for 3-4 weeks, and so on.



I`m sorry that you don`t agree with the structure, but when you consider the fact that tens of thousands of people have read the report and each expects something different from it, there never is a "perfect answer."

[Scottwax]

Originally posted by JB in Irvine

Instead of just giving a single initial grade for performance you chose to evaluate the look of the wax every week for 8 weeks. The purpose of that was no doubt to access the staying power or durability of the wax. Therefore durability is factored into the 8 week average performance score.



I have explained this point 3 times now and 3 times you have ignored it. :(



I think you are missing the point. The appearance was graded weekly over 8 weeks. I think that is completely fair and most people probably would like to know how the appearance holds up. Yes, durability will affect it and waxes that don`t last will recieve a lower score but to only factor in the appearance when the product is initially applied isn`t the way to go. Meguiars #26 for example would have been downgraded because it looked better a week after application than it did initially. Since the Guru test gives the ratings week by week, if you prefer looks over durability, then you can use the weekly ratings to decide to use product `a` looks very good for 4 weeks and you are willing to wax that often.

[Onehole]

Originally posted by geekysteve

Obviously as a wax wears away, the optics will suffer. This is by very definition the durability of the wax.




However, to say that we double counted the durability as a result is highly inaccurate. Sorry I have to disagree. Your assessing the preformance of the wax as it wears away and the seperately assessing how quickly it wears away. :(




How upset would folks be if after 8 weeks we just assigned a single grade of "whatever" for a product`s performance? Nothing wrong with a weighted score over 8 weeks. This takes into account the durability of the wax.




I think most folks would agree that they`d rather see how the things like depth, clarity, reflectivity, shine, gloss, etc. fared week-by-week because then they can determine for themselves which waxes suit their needs best. Some folks want a wax that looks great for a week, others expect the looks to remain constant for 3-4 weeks, and so on. Agree. But what you are assessing (and scoring) is durability.

[Onehole]

Originally posted by Scottwax

I think you are missing the point. The appearance was graded weekly over 8 weeks. I think that is completely fair and most people probably would like to know how the appearance holds up. Yes, durability will affect it and waxes that don`t last will recieve a lower score but to only factor in the appearance when the product is initially applied isn`t the way to go. Meguiars #26 for example would have been downgraded because it looked better a week after application than it did initially. Since the Guru test gives the ratings week by week, if you prefer looks over durability, then you can use the weekly ratings to decide to use product `a` looks very good for 4 weeks and you are willing to wax that often.



I agree 100% scoring each week is correct in calculating the Overall Performance.



HOWEVER the overall grade point average is calculated as:

40% Overall Performance

30% Durability

20% Ease of Use

10% Availability



So a wax with poor durability will score poorly in the Overall Performance (because its calculated over 8 weeks) and then again will score poorly in the Durability score.



This to me, is factoring durability into to seperate parts of the overall GPA. Thats my point.

[Scottwax]

Originally posted by JB in Irvine

I agree 100% scoring each week is correct in calculating the Overall Performance.



HOWEVER the overall grade point average is calculated as:

40% Overall Performance

30% Durability

20% Ease of Use

10% Availability



So a wax with poor durability will score poorly in the Overall Performance (because its calculated over 8 weeks) and then again will score poorly in the Durability score.



This to me, is factoring durability into to seperate parts of the overall GPA. Thats my point.



I realize that, but with the weekly rankings, you can use it to chose the wax that looks good for the length of time you are willing to go between wax jobs.



I don`t really see any other way to rank appearance though. It holds up or it doesn`t. :nixweiss

[Jcrawford]

Originally posted by JB in Irvine

I agree 100% scoring each week is correct in calculating the Overall Performance.



HOWEVER the overall grade point average is calculated as:

40% Overall Performance

30% Durability

20% Ease of Use

10% Availability



So a wax with poor durability will score poorly in the Overall Performance (because its calculated over 8 weeks) and then again will score poorly in the Durability score.



This to me, is factoring durability into to seperate parts of the overall GPA. Thats my point.



breath easy...it`s just wax.

[Onehole]

Originally posted by JCrawford

breath easy...it`s just wax.

lol...yes it is. :)

[Onehole]

Originally posted by Scottwax

I realize that, but with the weekly rankings, you can use it to chose the wax that looks good for the length of time you are willing to go between wax jobs.



I don`t really see any other way to rank appearance though. It holds up or it doesn`t. :nixweiss



Again I agree. :up



I`m not disagreeing with the way the Performance Score was calculated at all.