Porbability, not sure I get it

  • Thread starter liquidFuzz
  • Start date
In summary, the conversation discusses calculating probabilities using Bayes theorem and determining the probability of something happening versus the probability of something going wrong if that certain event happens. The text also mentions the importance of clearly stating where the probabilities come from and not having probability values above 1.
  • #1
liquidFuzz
97
3
An example of what I try to calculate. In a string matching between two strings the whole strings aren't compared, just a section.

A = The probability of a true hit.
A true hit being:
PHP:
|adcbacdcbacd|abacd
|adcbacdcbacd|ab

B = The probability of artifact being correct.
Falls artifact being:
PHP:
|adcbacdcbacd|abacd
|adcbacdcbacd|bca

I though I'd use Bayes theorem to calculate the probability, but I'm not sure of how to do it.
[itex]P(A|B)\frac{P(B|A)P(A)}{P(B)}[/itex]

In my example A is much higher than B, would this imply:
[itex]P(A|B)\frac{P(≈A)P(A)}{P(B)} ≈ P(A)[/itex]
 
Mathematics news on Phys.org
  • #2
I don't get what you want to calculate.
Can you add a general description instead of 2 uncommented examples?
 
  • #3
mfb said:
I don't get what you want to calculate.
Can you add a general description instead of 2 uncommented examples?
A = Probability of something happening
B = Probability of something goes wrong if A happened.
 
  • #4
That is not the problem.
What do you want to calculate, where do those probabilities come from, and so on?

B = Probability of something goes wrong if A happened.
So P(B) is P(goes wrong|A)?
 
  • #5
Ok, I snitched the text that got my puzzled. Please comment!
 

Attachments

  • Bayes.png
    Bayes.png
    30.7 KB · Views: 424
  • #6
Did you have a particular question in mind given your snitch?
 
  • #7
Yeah, I don't quite get the part when he or she goes all P(A|B) and P(B|A).

This is a part of a report that I'm helping to proofread.
 
  • #8
Probability values above 1 do not make sense. In addition, the text does not state clearly where probabilities come from. It is like "probability of an apple" - sure, I know apples, but an apple where, in which setup?
 
  • #9
I guess I'll get away with just commenting this. "Vague reasoning."

Thanks!
 

What is probability?

Probability is the measure of the likelihood of an event occurring. It is a number between 0 and 1, where 0 represents impossibility and 1 represents certainty.

How is probability calculated?

Probability is calculated by dividing the number of favorable outcomes by the total number of possible outcomes. This can be represented as a fraction, decimal, or percentage.

What is the difference between theoretical and experimental probability?

Theoretical probability is based on mathematical calculations and assumes all outcomes are equally likely. Experimental probability is based on actual trials or experiments and may differ from theoretical probability due to chance or random factors.

Can probability be used to predict future events?

Probability can be used to make predictions, but it cannot guarantee the outcome of a future event. It is based on past data and assumes that the same conditions will apply in the future.

How is probability used in real life?

Probability is used in various fields, including science, economics, and statistics. It can be used to make decisions, assess risk, and analyze data. For example, in medicine, probability is used to determine the likelihood of a certain treatment being effective for a patient.

Similar threads

  • Calculus and Beyond Homework Help
Replies
6
Views
855
  • Set Theory, Logic, Probability, Statistics
Replies
19
Views
1K
Replies
1
Views
587
Replies
5
Views
2K
  • Precalculus Mathematics Homework Help
Replies
11
Views
2K
  • Set Theory, Logic, Probability, Statistics
2
Replies
47
Views
3K
Replies
4
Views
2K
Replies
6
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
284
  • Beyond the Standard Models
Replies
0
Views
1K
Back
Top