Statistics about the amount of saved food

discussion
feedback
#3

Currently, we only calculate the sum of feedback weight. If two people gave weight for the same pickup, it is being averaged. The idea from @Teddy to calculate average weight per weekday sounds interesting, I’ll look into it when we have a bit more feedback gathered on karrot.world.

I’d love to make good estimates about the amount of food picked up, but I fear that it’s quite hard. There’s so many things that karrot usually doesn’t know about, for example holiday seasons, big events or the employees having a bad day…

#4

I think the feedback function is a very important feature, as it is essential to account the amount of food that was saved.It is already very nice to have the number of pickups, number of feedbacks and amount of saved food. With this data it is also possible to calculate some stats (e.g. monthly) manually …

What is a problem here in Taiwan is that many people seem to have problems to estimate the amount of food they have picked up. Like sometimes I see pictures with huge amounts of food and when I check the feedback it says 500 g… and people have gotten back to me and asked for help. Some people even asked me to provide scales at the stores, but I think we will try to maybe share some example photos to give them ideas of the weight.

#5

I know it’s a very old topic but I’m interested in stats and this odd fancy has brought me here. I have a question regarding this comment:

If two people gave weight for the same pickup, it is being averaged.

What is the logic behind this? In Warsaw when multiple people give feedback in Karrot, they put weight of what each of them picked up. So their weights shouldn’t be averaged but summed up. Sometimes it happens that only one person gives feedback with weight and then it represents total weight. In the light of the above, can we switch from average to sum to have better stats in Karrot?

I personally don’t think Karrot should do any estimates in terms of weights for pickups without feedback. No feedback may mean 0 kg or 100 kg. How Karrot is supposed to know this? Averages per weekday are just averages based on the history. They might be very wrong and stats should be based on facts not estimates.

There is a simple solution to have proper stats in Karrot. Request all Karrot users to add weights to their feedback. In Warsaw almost 100% of pickups have feedbacks in Karrot including weights. This is a commonly accepted rule to add feedback after the pickup and nobody questions the need to do that. I believe this discipline is much easier to achieve than creating a forecasting algorithm inside Karrot to predict weights of historical pickups.

#6

Yeah, that’s also something that gives me headache sometimes. I search through our history. I implemented it in this Pull Request, but the decision was already made before when the feedback feature was added. From this comment:

Should the weight be about the whole pick-up or just the amount that the foodsaver took home?
It becomes relevant when calculating statistics.

Reasons for asking for the weight …
(1) of the whole pick-up:

  • maybe some people have better overview/are better at estimating
  • if multiple users give feedback for the same pick-up event, we could calculate the average

(2) only of the amount the foodsaver took home

  • seems easier to estimate smaller amounts, which might give more accurate statistics
  • conflicting feedback about the total amount are avoided

As @bruno summarized in this comment, we seemed to favor (1) at that time. Back then, we wanted to implement estimates for the average weight per pickup and extrapolate.

The feedback weight input says “Amount of food all of you were able to save (in kg)”. But it seems it’s difficult to tell them otherwise, probably because it’s too difficult for them to estimate the weight of the whole pickup.

I would consider it, although not retroactively. There are many people who entered the numbers the way Karrot told them to, and I wouldn’t want to break their feedback.

Fair point, and I think our planning came from a time when we expected only a small number of users to enter feedback. Now that it’s different and we should reconsider.

Advantage of not doing extrapolation:

  • users have more reason to give feedback; might give more accurate numbers
  • it is essentially the status quo
  • less complexity; easier to understand

Potential problems of having a direct connection between feedback weight and weight statistics:

  • users might be tempted to set higher weight to make their pickup statistics look nicer (user statistics do not exist yet, but well…)
  • variance of estimation bias between different people doesn’t cancel out

Overall, I think it would be a good choice to “say no” to more cleverness in software, it might get in the way of humans. Rather accept human error and try to nudge them in a good direction (e.g. by showing hints how to estimate weight).

#7

You are right. I’m using Polish version of Karrot and this sentence has been translated to something like: “Amount of food you saved (in kg)” which doesn’t indicate it should be a total for the whole pickup. The translation has introduced confusion here, however, I still favour the option to put weight of the food each person saved not a total amount :slight_smile:

Makes sense. I agree.

I agree 100%!

#8

I totally agree and now I actually don’t know what we should do in Warsaw. Since always we have been underestimating what we’re saving. Well, bad, but cannot be changed. What should we do not? Should we tell everyone that it works differently than we thought??? Or rather just wait until it works as we always thought it is? Going back and forth will be difficult - any change takes a lot of time to get used to it. What do you think? It of course depends on how long this would be.

#9

Hard to say. Maybe really just wait?

I think rather software should change than people. So we just need more people to change the software :wink:

#10

An interesting and hopefully not a complex request was raised by one Foodsaver in Warsaw group. It consists in adding a day of the week to the date of the feedback, e.g. instead of: Apr 24, 2019, 9:45 PM let’s make it: Wed, Apr 24, 2019, 9:45 PM. This simple change should allow everyone to see if there is any tendency in the amount of food we have been picking up in a given store. If there are some regularities, e.g. a lot of kilos on weekends and not so many on weekdays, it will be a valuable information for everyone before signing up for a pickup. Some Foodsavers have means to pick up any amount of food, while others may be limited to small pickups. When they know what they can expect on a given day of the week, they can make wiser choices.

Let me know what you think.

2 Likes
#11

Sounds good, I changed it. Will be released in the next days!

1 Like
#12

Great Work! Thanks to all of you frequently improving karrots.

Don’t make the feedback too complicated.
It is clear, that

  • in case of one person is picking up: total amount is stated by that person.
  • in case of more than one person is pickung up togehter it depends:
    – total amount is stated by one person, if all staff goes to that person;
    – every person of a pickup is stating own amount, if the staff is shared.
    (The above version is the most logical and practical one, because those persons taking away the stuff are knowing best, how much and what it was. And with this system we will have an idea which amount of goods the individual foodsaver has picked up.)

It would be great, if we can also get an “annual -total” of the amount per shop.
It would be great too, if we may get an total amount per foodsaver.

Thanks a lot again to all of you!!!
Sylvia

1 Like
#13

Please remember that currently if two people give feedback, Karrot assumes both are for the total amount and it gets averaged:

I also prefer the logic when each foodsaver comments on their own amount not on the total :slight_smile:

#14

I have it on my list to change this behavior; will notify you in here when I started working on it!

1 Like
#15

It’s not that evident, since foodsaving groups can be quite different. In our case for example there are many pickups (most actually) which we do together, take all the stuff to a sharing place, first share among food savers and leave the rest at the sharing place. So what to make of all the food saved and that is not taken by the foodsavers, but left to share somewhere? Sometimes it’s more than what foodsavers themselves will take home.

That is the reason why I prefer the current system of people estimating the total amount and Karrot making an average. This contemplates both use cases where pickups can be done by a single person and they take all or by many people and they take all or leave at a sharing spot.

#16

The current system doesn’t help in a situation when many people don’t go to the sharing spot together and the simply don’t know what is the total amount. In the new one, when amount entered by each Foodsaver is summed and not averaged, you can still agree who enters the amount which is left at a sharing spot.

#17

That is probably again the case of foodsaving groups working differently. When people save the food at a store here they will always see the total amount of food saved and can guess on that, even if they don’t go all the way to the sharing spot.

There is definitely not a one-size-fits-all solution for this feature, so I think we need to continue to investigate more the different realities of the groups using Karrot before changing the feature.

#18

Not really. Sometimes there is so much food that it’s not really possible to assess the total. And we rather not guess the amount of saved food but either weigh it or estimate it, for example, by knowing the average weight of the item and multiplying it by its count. We don’t do it during the pickup though which has to be done quickly but later when we take food home to pack it into portions ready to be left at a sharing spot. That’s why each Foodsaver cannot take responsibility for the total amount because they don’t know total amount. We want to keep stats reliable and we don’t want our users to just guess what the total amount should be.

In your case, when each Foodsaver is able to assess total amount, why couldn’t they assess the amount they are carrying? Total will be a sum of individual assessments. It’s not that different than an average of individual assessments.

#19

I assume you’re speaking for your group. In our case we actually do an assessment even if it’s hundreds of kilos, by multiplying the number of banana-boxes (the standard we use in transporting in many cases) by 10 kg, or just by a simple visual assessment. That is obviously inaccurate and a gross estimation, but it’s not our concern (and I believe most of the groups) to spend time weighing things properly.

Usually the people who do use the feature, which are a minority here, are the ones with a bit more experience and feeling more confident about guessing the total amount.

Because many times they do the collection and transportation of the food together and it does not make sense to think only of the amount they are individually carrying. We could say then that people would input the amount of food they got to themselves, that is, what they brought home with them. That’s another measurement. The feature could be changed and used to estimate that, but then it should be clear and then our group (and maybe other groups that leave considerable amounts at sharing spots) would have to decide on one person who reports their personal share plus the amount of food left in sharing spots.

#20

If you are not really interested in having reliable stats, why does it matter to you how this feature works? :slight_smile: In our group 99% of pickups have quite detailed feedback with quite detailed weights. That’s why I’m insisting on not spoiling our evaluations by averaging the amounts.

This is hardly the purpose of this feature. We want to keep record of saved food, not food taken home.

Maybe one person can give feedback with total amount then? If not many users in your group use this feature, it shouldn’t be a big deal, right?

#21

to mzpawlowshi: I share your opinion completely!

E.g. for us (EfA - in Germany) the feetback feature, with detaild and realistic amounts for each shop and each foodsaver, is crucial and we use it all the time.


Especially if so many foodsaving groups are working in a different manner
an algorithm to built an everage or what ever will confuse people, would make the system less detailed and correct but more complicated.

In our group we often pickup the staff with several persons and in most cases, about 90% will be carried e.g. to varous Kindergarden and so on. Only about 10% is for private use.

For example 3 foodaver are picking up the total amount of about 50 kg net weight of goods (excluding the rubish) in one market.
1 foodsaver is carrying 45 kg fruits and vegetable for Kindergarden No1,
1 is taking 5 kg chocolate for Kindergarden No2, the other foodsaver helped but carried 0 kg.
We would prefere, if everyone can state the real amount and may give comments.
Statistic should show 50 kg as tolal amount, and nothing else (not a total of 25kg and not a total of 15kg fruit-vege-late).

1 Like
#22

Oh, what a heated discussion! I’d like to take a step back and would be interested why the pickup weight is useful and/or important to you. That would help me a lot to implement good statistics :smiley: