stat - eric In the cingulotomy research which of the following would be important to know to assess the effectiveness of an MRI-guided cingulotomy for

stat - eric In the cingulotomy research which of the...

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eric: In the cingulotomy research, which of the following would be important to know to assess the effectiveness of an MRI-guided cingulotomy for treating psychiatric disease?i) The fraction of psychiatric patients in general who recover from severe psychiatric symptoms that last a year or longer. ii) The effect of a cingulotomy on people without mental illness.iii) The number of patients whose follow-up evaluations were based on letters from them, rather than assessments by a psychiatrist. Megan Goldman: What do you think on this one? eric: i realized that this was in one of the previous hw too eric: so iget why i) is true eric: and ii) eric: but not iii), lol Megan Goldman: Right, that'll help sort out if this treatment has any different effect from whatever most psych patients are doing. eric: iii seems somehow irrelevant to me? Megan Goldman: Well, the follow-up from letters isn't as reliable as from a psychiatrist. Megan Goldman: If it turns out that a huge portion of the follow-up was done with letters, it may call teh results into question. Megan Goldman: Patients may tend to over/understate their symptoms when self-reporting. eric: oh i see eric: is this correct if i call this response bias? Megan Goldman: Self-reporting is prone to response bias, yes. eric: right ,okay eric: cool Sean: Hi Megan Sean: can I ask you about question 20 on Final 3? Megan Goldman: Sure. Sean: it's the which of the "following is closest ..." one Sean: I think I'm supposd to use the inequalities here, but I Sean: 'm kinda confused Sean: i tried doing 16292.64/3992.655
Sean: to get ~4 Sean: then 1/4^2 Sean: and got abou 6.25% Sean: am i supposed to subtract that from 100% to get the right answer? Sean: I was using chebychev's inequality Megan Goldman: Let me noodle it out real quick. Megan Goldman: you've almost got Chebyshev right... it measures the distance from the mean, so you'll want (16292.64 - 3915.413)/3992.655 to get a value for k. Megan Goldman: Then do 1/k^2 to find a probability .... Recall that the probability is the chance of being *outside* that many SDs from the mean. Sean: oh so there is ~10% chance that it's that many SDs outside from the mean Megan Goldman: So yes, you'll want 1 - that probability to find the chance you're less than that many SDs away. Megan Goldman: Right. Sean: icic Sean: for the 16292.64-3915 / 3992.655 part Sean: is that converting to SU? Megan Goldman: Basically, yes. Sean: i see Sean: thank you :) Megan Goldman: No prob. Tina: Hi megan Megan Goldman: Howdy Tina: can you help me right now or are you with another student? Megan Goldman: No, go ahead. Tina: oh ok well I'm having trouble on Q6 Tina: finding the P-value Tina: I know how to find Z
Megan Goldman: Alright. did you get an answer to Q5? Tina: yes Megan Goldman: We're not on to z yet here... that would be using teh normal approximation for Fisher's Exact Test. Here, we're using Fisher without approximation.

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