[koolkelv]

I know that only about a hundred odd people will do this exam but out of those on here, anyone done any revision for it? Anyone got any tips or revision notes to share because I've not done any revision at all

[Sharma93]

I've just gone through the whole syllabus, so:

Probability Density Functions
Expectation Algebra
Sampling
Confidence Intervals
Wilcoxon
T-Test
Chi-Squared Goodness of Fit Test

I think those are the bases I've covered...

[Benniboi1]

Haven't had time to do any since May, will start tomorrow afternoon just nail the basics of each topic and it will be alright

[james20207]

Hey guys, can anyone give me info on the different sampling techniques (simple random, systematic, stratified, cluster, quota and opportunity) as in definitions and how you would carry them out? I'm self teaching myself S3 rather than doing M3 with my class

[koolkelv]

(Original post by james20207)
Hey guys, can anyone give me info on the different sampling techniques (simple random, systematic, stratified, cluster, quota and opportunity) as in definitions and how you would carry them out? I'm self teaching myself S3 rather than doing M3 with my class

Do you not have the textbook?

I'll copy out the definitions for you.

Simple random sampling procedure is when every possible sample of a given size is equally likely to be selected. Note the converse is not true, i.e. if ever item is equally likely to be selected, it may not be simple random sampling.

Stratified sampling is when you ensure every strata of a sample is sampled, where a strata is a sub-group.

Proportional stratified sampling is when every strata are sampled proportional to its size.

Cluster sampling is when you choose from one or several of the clusters/sub-groups. (Don't quite understand this but I think it has to do with the inaccessibility of the parent population and so you choose one or two clusters which you represent the whole population with.)

Systematic sampling is a method of choosing individuals from a sampling frame. You do this by selecting a random number, and then picking samples that are a multiple of that number, or example if you choose 6, then every 6th sample would be chosen. Be aware that this may be flawed method if you sampled a school of class size 20 and ordered from not clever to clever, then a systematic sample of 20 means that always the brightest students will be picked.

Quota sampling is not random. You pick a quota of things to be sampled in the parent population or a quota for each sub-group, but then the sampling technique used is up to the person who you pas the quota to.

[james20207]

(Original post by koolkelv)
Do you not have the textbook?

I'll copy out the definitions for you.

Simple random sampling procedure is when every possible sample of a given size is equally likely to be selected. Note the converse is not true, i.e. if ever item is equally likely to be selected, it may not be simple random sampling.

Stratified sampling is when you ensure every strata of a sample is sampled, where a strata is a sub-group.

Proportional stratified sampling is when every strata are sampled proportional to its size.

Cluster sampling is when you choose from one or several of the clusters/sub-groups. (Don't quite understand this but I think it has to do with the inaccessibility of the parent population and so you choose one or two clusters which you represent the whole population with.)

Systematic sampling is a method of choosing individuals from a sampling frame. You do this by selecting a random number, and then picking samples that are a multiple of that number, or example if you choose 6, then every 6th sample would be chosen. Be aware that this may be flawed method if you sampled a school of class size 20 and ordered from not clever to clever, then a systematic sample of 20 means that always the brightest students will be picked.

Quota sampling is not random. You pick a quota of things to be sampled in the parent population or a quota for each sub-group, but then the sampling technique used is up to the person who you pas the quota to.

Nope, no textbook just been learning it all using the spec and past papers which was a bad idea! And thank you so much for typing it out, it has helped a lot!

[koolkelv]

(Original post by james20207)
Nope, no textbook just been learning it all using the spec and past papers which was a bad idea! And thank you so much for typing it out, it has helped a lot!

No problem, typing it out also made me learn it as well

Still not confident though, did the jan 2012 paper and did terrible things. I couldn't do any of the last question, which was about cumulative distributions :/

[ryanboi]

(Original post by koolkelv)
No problem, typing it out also made me learn it as well

Still not confident though, did the jan 2012 paper and did terrible things. I couldn't do any of the last question, which was about cumulative distributions :/

Hey mate, do you think you can tell me the name of the S3 textbook you are using for AQA? Thank you I am thinking of taking S3 aswell next year. Btw is S3 AS module or A2 module?

[koolkelv]

(Original post by ryanboi)
Hey mate, do you think you can tell me the name of the S3 textbook you are using for AQA? Thank you I am thinking of taking S3 aswell next year. Btw is S3 AS module or A2 module?

I was doing MEI exam and it's an A2 module