Google Interview Question
Applications DevelopersCountry: India
A 3 step strategy can be used:
1> Real time filter on the date, time and range of IP addresses from where clicks to a ad link are originating
2> Offline analysis of the click ad log files over past days comparing the number of ad clicks for a particular ad link from range of IP addresses
3> Human and machine investigation into false ad clicks involving the company paying for the ad considering data from other ad networks, market conditions, etc.. as required.
why would someone click on an ad if there is captcha...already hardly anyone clicks on ads.....its bad for business....
i said this and immediately took back my words citing the same reasons...interviewer agreed....
Ok..so instead of using captcha, some other advertisement should be displayed in between and a click button saying "skip to Advertisement".. only a human user would be able to click and identify this.
draw a pattern like android connecting the dots unlock app.
Tell user to do this: hold mouse button for 3 seconds to see the add.
Various click combinations right+left+right and so on...
@anon...still not sure how would it help.
@aka: any delays that might prevent clicking on ads would be deterent to business per my view and hence not acceptable...
Will monitioring the number of clicks from an IP be feasible? It might be more of analytics rather than run time check.
arun..it need not be run time..
i mentioned the same thing as one of my points....try to make some patterns of ads being clicked by one IP address
at least..he seemed ok..
problem is not about finding this necessarily at run time...it could be you have millions of data..you need to identify false clicks.
Probably, you can use this info to prevent this in future and calculate the correct amount of payment that can be done...last point is solely my judgement
1. Min time interval between clicks
2. From which ip/area(router) it is coming
3. max num of clicks in a given interval (~ 1 min)
4. If time intervals between clicks is regular(ex: equal could mean a bot)
5.
As far as I understand the question, the question is about how would you identify if the ad being clicked is by a genuine user or a script / virus.
Now for "this" question , I do not understand some of the solutions mentioned here.
1) The check for IP address is incorrect solution as for both the cases user/script the ip address would remain the same
2) People suggesting here to use some kind of captcha, click on this part of the ad, hold left mouse key for x seconds, press various key combinations : guys, the question is about how to "differentiate" between users and script from the click requests that have already come in, and not to "avoid" scripts.
Now I did like this solution : Look at which part of the ad is being clicked continuously by this IP. humans tend to click at different places.
But, to me the questions seems unanswerable as , if the script writer is intelligent enough, he would obviously know that his script should place clicks NOT at constant intervals but at random times and at random places of the ad.
So, this questions highly depends on what the interviews wants to ask you, assume script writer is not much intelligent and differentiate between clicks that have come already.
OR avoid scripts.
As far as I understand the question, the question is about how would you identify if the ad being clicked is by a genuine user or a script / virus.
Now for "this" question , I do not understand some of the solutions mentioned here.
1) The check for IP address is incorrect solution as for both the cases user/script the ip address would remain the same
2) People suggesting here to use some kind of captcha, click on this part of the ad, hold left mouse key for x seconds, press various key combinations : guys, the question is about how to "differentiate" between users and script from the click requests that have already come in, and not to "avoid" scripts.
Now I did like this solution : Look at which part of the ad is being clicked continuously by this IP. humans tend to click at different places.
But, to me the questions seems unanswerable as , if the script writer is intelligent enough, he would obviously know that his script should place clicks NOT at constant intervals but at random times and at random places of the ad.
So, this questions highly depends on what the interviews wants to ask you, assume script writer is not much intelligent and differentiate between clicks that have come already.
OR avoid scripts.
we can use the "no captcha" technique.. in which humans cant see any captcha with naked eyes (invisible), so proceed with the normal procedure, while the computer detect a captcha n thus getting caught/identified as non human
- sgarg June 15, 2013