IAM or RoADAR?

[Mr Cholmondeley-Warner]

"Imprecise operation of the indicator stalk"?

Call me naive, but surely there are more important things in life, or at least driving, that have a more direct impact on safety, than which way you grasp the knobs?

[MrToad]

I do tend to knock it on and off with the edge of the hand, whereas those with Police training will grip it between the fingers and move it more positively.

My way works fine for my car, but may be less transferrable to another vehicle than the recommended way. To be fair, it was only mentioned in passing.

More interesting is that the only two times it has been commented on were by ex-Police instructors.

[crr003]

"Imprecise operation of the indicator stalk"?

Call me naive, but surely there are more important things in life, or at least driving, that have a more direct impact on safety, than which way you grasp the knobs?

When I did RoADAR in your area, my pre test drive with another Tutor raised the same issue.

[crr003]

A calculation which is then multiplied by something sounds plausible - the actual figure was 89%.

Interestingly, two of the comments you made when we drove together last year were repeated during the test (sorry, assessment) - slightly close following position and imprecise operation of the indicator stalk. It appears that the things Police instructors look for are remarkably consistent across the country.

Congratulations on taking the SA and getting a score like that (even if we can't figure out how it's calculated!)

Re indicating style - did he want a hand removed from the steering wheel to operate the stalk?

[waremark]

Fenland Flyer posted an explanation last year - if I understand him correctly it would give 87% for 20 1's and 7 2's, 89% would suggest only 6 2's. Either way it is an excellent score; I am not surprised, I thought you drove exceptionally well when we went out together on 'Steering Day'. This is what FF said:

"Yes, we use the same form and the marking scheme is:- if, in the particular category, your technique is as good as the average IAM pass you get a 3, if it is better than average you will get a 2 and if you hardly put a foot wrong you will get a 1. Obviously if it is worse than average you get a 4 and a 5 speaks for itself!!

All the marks are added up and then divided into the total number of categories marked (not all the boxes are filled) and, just like that, the percentage mark appears. Therefore, if you get all 3's you get 33%, 2's give you 50% and 1's 100%. Simple really, it must be 'cause I can do it."

[Custom24]

Fenland Flyer posted an explanation last year - if I understand him correctly it would give 87% for 20 1's and 7 2's, 89% would suggest only 6 2's. ...

This is what FF said: ...

Can you explain how you arrive at 87%, since it is close to the true figure.

I came to 79.4% using FF's workings, as you reported in page 2 of this thread and again here.

Basically, my working was as follows;

7 2's = 14, 20 1's = 20, sum = 34

As FF said, divide total "into" number of categories marked, 27/34 = 79.4%. Not sure what he meant by "into", but obviously we don't want a score above 100%, and the above method is consistent with the examples he posted for all 1's, all 2's etc.

The only other way I can think of would be a simple % of the total possible mark, for which we need to convert the scores so the 1's become 5's, 2's become 4's, etc

Then, the max score from 27 categories would be 27x5 (135)
Our SA candidate scored 20x5 plus 7x4 (128), equals 94.8% of the max mark, which is how I think some of the other guessers on here have arrived at that figure.

This is puzzling me.

[Fenland Flyer]

Sorry Mr. Toad but 7 x 2's and 20 x 1's gives a mark of 74% so either the numbers or the percentage you gave is wrong. I'm not saying you got it wrong, just that the two do not 'add-up'. Whatever figure is correct it doesn't detract from what must have been a very good drive.

[Custom24]

74%

How so?

[Gareth]

From FF as related by waremark, for each category a '1' gives 100%, a '2' gives 50% and a '3' gives 33% ...

So 20 scores of '1' give 20 categories at 100%, and 7 scores of '2' give 7 categories at 50%.

Add up the totals for all the categories: 20 @ 100% + 7 @ 50% = 2350%

Then divide by the number of categories: 2350% / 27 = 87%

If this is wrong, then the explanation included earlier isn't clear enough!

Mark, your calculation appears wonky because you appear to be giving more weight to categories marked with a '2' than those marked with a '1' ...

[ScoobyChris]

The only other way I can think of would be a simple % of the total possible mark, for which we need to convert the scores so the 1's become 5's, 2's become 4's, etc

This would make more sense to me as the number of categories should dictate the maximum mark. If you assume that a 1 is worth '1', a 2 is worth '1/2' and a 3 is worth '1/3' in line with what was mentioned above then you get:

(20 x 1) + (7 * 0.5) = 23.5
Maximum mark available is 27 (also the number of categories)

Therefore, percentage score would be 23.5 / 27 which is around 87%

Had it been 6 '2's then the percentage would have come out at 89%.

Of course, I know nothing so may be way off the mark

Chris

[ScoobyChris]

Damn Gareth's parallel posting

Chris

[MrToad]

Examiner error in my favour, collect 2 extra percent?

I've just looked at the report again, and the figures I've given are correct. I think I'll just keep my head down and stay quiet.

[Gareth]

7 x 2's and 20 x 1's gives a mark of 74%

Turning things around, if a '1' in a category is the maximum mark for that category, and if all categories have equal weight, then in MrToad's case each category contributes up to approximately 3.7% of his total score. Since he has 20 categories with a '1', they alone would get a total score of 74%.

I suppose the question is whether the categories marked as a '2' contribute to the total score. For MrToad to get an overall 89%, then the remaining 7 categories together provide an additional 15%.

Allowing for rounding errors, it appears that the scoring is as follows:

((20 x 1) + (7 x ?)) / 27 = 0.89

(20 x 1) + (7 x ?) = 24 (approx)

? = 4 / 7

which is an odd weighting to give for a category score of '2'. I think the "2 percentage points in your favour ..." theory looks most likely although I'll not try to guess the reason why

[Fenland Flyer]

I might well have a maths degree but it doesn't stop me pressing the wrong button, I should have given Mr. Toad 79% in my previous post, which is a very good mark (but then Andy Poulton is a pussy cat )

[Gareth]

I should have given Mr. Toad 79% in my previous post

Hmm, reworking the calculation:

((20 x 1) + (7 x ?)) / 27 = 0.79

(20 x 1) + (7 x ?) = 21 and 1/3 (approx)

7 x ? = 4/3

? = 4/21 which is approximately 1/5

so that's the weight FF gives to a mark of '2'.