1 / 33

Understanding Standards Event

Understanding Standards Event. Higher Statistics Award. Hypothesis Testing David Young Department of Mathematics & Statistics University of Strathclyde NHS, Greater Glasgow and Clyde. Overview. Welcome to the University of Strathclyde i ntroduction to SQA level 6 Statistics Award

fite
Download Presentation

Understanding Standards Event

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Understanding Standards Event Higher Statistics Award

  2. Hypothesis Testing David Young Department of Mathematics & Statistics University of Strathclyde NHS, Greater Glasgow and Clyde

  3. Overview Welcome to the University of Strathclyde • introduction to SQA level 6 Statistics Award (SQA Home > National Qualifications > Subjects > Statistics Award (SCQF level 6) • how statistics can answer important questions • practical sessions using Minitab and/or R

  4. What is statistics …? • statisticsis the science of collecting, analysing, presenting and interpreting data • it enables the objective evaluation of research questions of interest • it provides the means to weigh up how much evidence the collected data provide for and against the research hypothesis of interest • statistics are available on almost every aspect of daily life

  5. 2014 – the year of the selfie • millions are shared each and every day across all the major social media platforms • according to data from Samsung, selfies make up almost one-third of all photos taken by people aged 18-24 • Facebook, WhatsApp, Twitter, Instagram and Snapchat bearing the brunt of that load • Link – http://www.adweek.com/digital/selfie-generation/ • Twitter’s most retweeted post of all time … • Twitter’s most retweeted post of all time • …

  6. Use this slide for large images, graphics or tables.

  7. Addressing important questions • Can you get diabetes from eating too much sugar? • What are the side effects of too much vitamin D? • Is smartphone addiction a real phenomenon? • Does eating turkey at Christmas make you tired? • Does vitamin C make you look younger? • Is paracetamol better than codeine for treatment of pain? • ‘Two heads are better than one’. • Statistics can be used to answer such questions

  8. Not always a clear answer … • turkey makes you tired because it’s loaded with tryptophan • tryptophan is a pre-cursor to serotonin which is a mood modulator, inducing relaxation and supporting sleep • tryptophan alone does not make you tired • combining tryptophan with carbohydrates does • it is not the turkey that’s causing Christmas sleepiness, it’s the turkey plus the cranberries, rolls, and pie • turkey actually has less tryptophan than chicken

  9. Drug development • pharmaceutical companies have to gather data on drug performance • a drug cannot be used commercially until the company have produced evidence of efficacy and safety • statistical tests (known as hypothesis test) can be used to gather this evidence

  10. Omeprazole • Omeprazole (Prilosec, Zegerid) belongs to a group of drugs called proton pump inhibitors • it decreases the amount of acid produced in the stomach • Omeprazole is used to treat symptoms of gastroesophageal reflux disease(GERD) and other conditions caused by excess stomach acid • common side effects may include: stomach pain, gas, nausea, vomiting, diarrhoea or headache • https://www.drugs.com/omeprazole.html

  11. Statistics and Probability • statistical analysis considers the probability of an event being due to chance • can never be 100% certain for example that one treatment is better than another • can say mathematically how sure we are that a result is true

  12. Probability • hypothesis: all dogs can bark • how would you prove this? • data has to be gathered to give evidence for or against the hypothesis • a hypothesis test has to be performed

  13. Pain assessment score

  14. Hypothesis Testing

  15. Hypothesis Testing

  16. Hypothesis Testing

  17. Hypothesis Testing

  18. Hypothesis Testing

  19. Hypothesis Testing

  20. Hypothesis Testing

  21. Hypothesis Testing

  22. Hypothesis Testing

  23. Hypothesis Testing

  24. Hypothesis Testing

  25. Hypothesis Testing

  26. Interpretation • If the difference was not due to chance why did it happen?

  27. Interpretation • If the difference was not due to chance why did it happen? • When is this claim valid?

  28. Interpretation • If the difference was not due to chance why did it happen? • When is this claim valid? • What are the consequences of getting it wrong?

  29. Additional Points • errors in hypothesis testing – p<0.01! • null and alternative hypotheses • cranberry juice – randomisation http://www.ncbi.nlm.nih.gov/pubmed/22961092

  30. Additional Points • double blind studies • http://www.theguardian.com/society/2005/jan/17/health.medicineandhealth • placebo trials • comparison of baseline characteristics • intention-to-treat and per-protocol – weight loss example • tests for correlation, regression and normality testing

  31. Two heads are better than one …? • study design? • what were the rules for doing the quiz? • randomisation? • double blind? • how many participated – why is this important? • who marked? • are you satisfied that the groups were comparable?

  32. WWW.sqa.org.uk│0303 333 0330

More Related