Rating : calculations

[Blandine-AA]

There are 3 values when rating a location: Yes / No / NA (Not Applicable).
NA is the same as Yes. The criteria does not apply, therefore the site is accessible for that criteria.
Yes = 1 ; No = 0

The main question is what should be the value of NA? Do we assign it a 1 as Yes or do we give it some weight as it may create some issues because of users misunderstanding of what it means.

The status now for the value pf NA is :

• 1. Clarify the criteria so to remove any ambiguity, for the user to have clear choice of answers. JMCC is working on this.
• 2. Give NA a value calculation, for example NA = weight*Yes. weight=1 by default
• 3. Provide information on the NA button for each criteria to help the user in his choice, either when the user selects NA or when hoving over it. Final design to be provided later.

My suggestion is to do 2 and 3 now, while we are waiting for JMCC input to define the weight or equation for NA

[joshi1983]

I assigned this to Blandine because she needs to finish writing this issue before anyone can work on it.

[Blandine-AA]

Assigned back to you Josh. Please review and assign as appropriate.

[joshi1983]

What I've done so far to represent the information used in the Bus Station accessibility report is use 0 for No, 1 for Yes and 2 for NA. The specific numbers for each won't really affect calculations or the user's experience, though.

The formula I used for universal ratings can be described by this:
universal accessibility rating for a given question =
average( latest answer for each user where (Yes or NA) means 100% and No means 0%)

universal accessibility rating for a question category =
average( rating for each question in the category)

universal accessibility rating for an entire location =
average( rating for each question category )

This means that all answers by a given user are ignored except the very latest by that same user. This reflects how we want only the most recent answer from any user. There may be 100's or more users rating the same location so we could still end up with a result between 0% and 100%.

I didn't implement a personalized accessibility rating calculations because we still didn't get any answers to the wiki questions given before the last meeting at JMCC.

@Blandine-AA do you have more questions?

[Blandine-AA]

@joshi1983 I will answer the Universal and Personal view in #109 issue as for me it is separate from the value we give to each answer when rating a criteria whether the same user rates it once or 10 times.

I will put checkboxes on this issue to identify what needs to be implemented.

I will also update the wiki with the answers from the meeting with JMCC. I believe I shared those answers with you already.

[Blandine-AA]

@joshi1983, at the last meeting with JMCC, it was agreed to implement the NA calculation as defined in checkbox 2 of the issue description. For now, NA=Yes and Weight=1. Do not hard code NA value, but implement the equation provided.

I agree with your statement

This means that all answers by a given user are ignored except the very latest by that same user. This reflects how we want only the most recent answer from any user. There may be 100's or more users rating the same location so we could still end up with a result between 0% and 100%.

[joshi1983]

It has been a while since looking at this.

This is pretty obvious but just wanted to expand anyway:
NA = Not Applicable

I guess we also want a "didn't look at this" button too, right? Since this would need to be saved, it would need a special meaning too. For calculating the overall rating, the latest value being "didn't look at this" would count as not answered at all, right? In other words, the user might aswell not have hit that option at all. The importance of it may be to cancel the submission of another answer that he didn't mean to submit.

[stephanosm]

I just tested the "Windsor Public Library - Central Branch" and probably we don't need it. If you simply ignore it then it means i didn't look at this. Obviously, if you have a button is better in order to avoid any possible confusion but I worry we may not have enough space to add another button.

[stephanosm]

Also, I evaluated only few criteria of the "Windsor Public Library - Central Branch" just to check the rating algorithm. The calculation should take into consideration only the criteria that have been evaluated. Currently, it takes them into consideration. For example, if you rate as accessible 1 criteria out of 10 of one area (e.g. Parking) it will give you 10% accessible which in reality it should have been 100% because it is the only criteria you had a chance to see and evaluate.