Error Type (Type I & II)

[cleobabie]

The 5% outside of the confidence interval is distributed between the 2 tails, which means that each tail bears 2.5%, not 5% David.

[bionicturtledotcom]

@cleobabie not if one-tailed, i showed both, see (eg) @4:25. A CI (bound), like a test, can be 1 or 2-tailed (sided). A one-sided test, (eg., all VaRs), have the 5% significance in one tail

[lewiscooney]

I am thinking of burning all my textbooks and just using youtube

[bionicturtledotcom]

@lewiscooney interesting, what are these "textbooks" to which your refer, they sound familiar?

[lewiscooney]

@bionicturtledotcom medical statistics made easy. its the one my university recommends but I don't like it. It doesn't go into enough detail for me to actually apply it. When I used it statistics was an abstract unapplied thing that I couldn't actually use. If I was a bit cleverer maybe I could extrapolate from simple definitions and calculations but I need a helping hand to apply it to actual research papers and documents

[MyNASH111]

@bionicturtledotcom Hi..we say that it is not possible to minimise both the errors simultaneously..that is if we attempt to decrease type 1 error (alpha), the type 2 error increases. (beta)..but how can we prove this correlation between these two types of errors?? that is how can we show that a decrease in alpha increases beta..thanks..

[DURound]

Incorrect about the Census --- at least, if the Census is done correctly. Indeed, the word census means individual registration in the original latin.

[bionicturtledotcom]

@DURound Yes, agreed ... I had thought the Census was a sample, but as other commentors pointed out, a Census is an attempted survey of a population, so I did use a bad example. Thanks!

[kurt44ko]

this man may be retarded.

[EliteDoomer]

@kurt44ko Shut up you disrespectful fool.

[Ishayau]

I like your tutorials but this one was a little confusing.

May be this can help: Type I error – when we reject a “good” part as “bad”

Type II error – when we accept a “bad part” as “good”.

If the part is critical to safety we would prefer to make a type I error.

[vitalstrike82]

Thanks. This helps me to understand this concept.

[mpdp85]

@bionicturtledotcom lol YOU are kidding right? Census type data is the complete opposite of a sample. A census is an attempt to measure some population characteristic at a single point in time, a sample only looks at a subset and tries to infer. You have given a terrible example. a better example would be Television ratings. There is no way of knowing exacly what millions of people have watched, the only way of knowing is to monitor a small subsets viewing habits

[sanger786]

your vedios are very helpfull.

[sanger786]

excellent demonstrations. I have leraned a lot when see your videos.

[75cmv]

No - it is Constitutionally mandated that a count of every person is taken place, it is a massive and expensive undertaking by the Department of Commerce. There's an episode of the West Wing where they attempt to change this to sampling to improve accuracy and costs. It's unfortunate that you reinforce the Quant stereotype - brilliant but suffering from 'spreadsheet myopia'.

[lbrown1956]

No I am not kidding. That is what a census is. It measures every individual and it is required by the constitution that we count every person individually. Now it is true that inherently we are going to miss some. So people with knowledge in statistics are pushing to try to include some manipulation of the data to deal with these issues. They hire 10's of thousands to go around to every address in the US. They try to count the homeless by picking a specific night to measure them.

[ObliviousMin]

@lbrown1956 However, it is practically impossible to include EVERY individual in a nation-state. For example, in Singapore, where I come from, its only 50km wide +/-, yet still, it is practically impossible to include every single individual. The first and utmost reason is the practicality of the situation, and second, it should be economically pragmatic; inexpensive.

[lbrown1956]

What do you mean the census doesn't measure everybody, this is exactly wrong. They do measure the a set of specific characteristics of everybody. It is true that they don't measure certain characteristics of everybody but there is a base set that they do measure of everybody.

[jimmy5420]

So just a question, when do we use two tail and one tail test?

[ProBinderSpinner]

two tail is when the alternate hypothesis does not equal H naught.

one tail is when H alternative is greater than, or less than H naught

[slipknotpsychoman]

I thought you never want to "accept" the null. You either have sufficient evidence to reject the null or you cannot reject the null due to insufficient evidence.  Am I wrong?

[jayvoodoo]

I fail to reject your response!

[jimmy5420]

I think it depends on the situations.

[jlive1975]

you're a life saver david, im using your videos to help study for the Level 1 exam and they really help crystallize a lot of the quant material specifically. Thanks so much!

[rhettintaipei]

Agreed!! Keep them coming! You could consider recommending a favorite charity, I am sure people would donate:)

[tvij21]

sweet! man u are awesome in explaining these concepts visually !! i am a visual thinker & this helps tremendously!!

[enrique380]

Thanks for the video.