Credibility Score Algorithm


The idea behind this draft blog is to introduced a system to give Credibility Score (CS) to each subscriber to any social network or collaboration portal based on their contribution to the community. Their contribution here might be posting an article or a review, how the system builds CS for that user will be based upon subsequent reactions by other members and the amount of posts performed by that user.

How it works:

Whenever a user make any post of any kind in a social network, other users using this network will be presented with a rating mechanism to rate this post, the values used to rate the post are listed below and given weight for each category. By using all ratings the user has got for his post, the below process takes place to calculate CS for this post.

Credibility Score of a user is the sum of all CS for each post they earn. CS of a user can be then used to give weight for subsequent posts of the user, CS is a number between 0 and 1, where 0 means the user has no credibility and 1 means they have the maximum credibility.


Each rating will be allowed one of the following values:

Rating Weight
True 1.00
Mostly true 0.75
Half true 0.5
Mostly false 0.25
False 0
Ridiculous -1

Review credibility score:

  • For each review calculate total rating and divide them into 6 categories: true, mostly true, half true, mostly false, false and ridiculous
  • Calculate proportion value and credibility score for each category, for example, if a review has 29 ratings:
    Category Category weight Category count Proportion Credibility
    True 1 4 0.13 0.13
    Mostly true 0.75 16 0.55 0.41
    Half true 0.50 7 0.24 0.12
    Mostly false 0.25 2 0.06 0.01
    False 0 1 0.03 0
    Ridiculous -1 0 0 0
  • So the user has total of 0.67 credibility for this review

User credibility score:

  • Get total number of reviews committed by a user (for example a user has 5 reviews)
  • Get the total number of rating for user reviews (for example a user got 3 out of 5 reviews rated)
  • Calculate evaluation ratio (number of reviews rated / total number of reviews), for our example it’s ⅗ = 0.60
  • Calculate average credibility score for all rated reviews, for example of those 3 rated reviews got credibility scores: 0.67, 0.25 and 0.41 which is
    • (0.67 + 0.25 + 0.41) / 3 = 0.44
    • User unnormalized credibility score is 0.44
  • Multiply evaluation ratio with unnormalized credibility score to get the final credibility score for a user, so
    • User credibility score: 0.60 * 0.44 = 0.26
  • The more ratings a user get the higher their credibility score preserved

Note: might have issues for example if a user have only 1 review rated while they posted 75 reviews, so it doesn’t really reflect their true credibility

So for evaluating ratings done for schools, credibility score for a user will affect this rating by multiplying each rating done by the user with his/her credibility score, for example if a user give the following ratings:

Category Rating (out of 5) Rating after applying CS
Cleanliness 4 1.04
Transportation 5 1.3
Teachers 3 0.78


How to Combat Presentation Anxiety

Here is a nice article that I found somewhere over SlideShare talking about the subject (Scott Schwertly):

Last week, we discussed the difference between fear and anxiety. Our conclusion was that most presenters actually possess more anxiety than fear when it comes to presentations and public speaking. Given that reality, I want to unpack ways in which you can combat anxiety in your next speech.

Here are 3 essential tips:

1. Get the Blood Flowing

If you are a fan of exercise, then go for a run or walk the day of your talk. Studies have proven that the benefits of exercise have a positive effect on the nerves, lasting up to 12 hours. If you know you enjoy the endorphins that come with exercise, make sure you perform your activity within 12 hours of your presentation.

2. Rehearse, Don’t Memorize

Practice will build your confidence and reduce your anxiety. However, please note that there’s a significant difference between being well-rehearsed and coming across as memorized. Rehearsed implies that you are prepared, confident and can speak on the fly if needed. Memorized implies that you are dependent, lack confidence and are controlled by your talk, rather than you controlling it. Remember and run through key phrases and points, but don’t memorize word by word — the pressure of remembering all that will just add more to your anxiety!

3. Show Appreciation

Ultimately, you want to get into a mindset of appreciation. If your audience knows you want to add value to their life, you will immediately feel a sense of ease because it will define your purpose and role in the presentation environment. Simply, if you can demonstrate that you care about your audience, then they will be more likely to care about you. Perceived distance between the speaker and audience creates uncomfortableness.

Anxiety is a very subjective matter. At the end of the day, you know yourself better than anyone else, so choose those activities that will calm you best.