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1 Tile of Resource Hand Calculaion: -es for ependen Means(rugs & Learning) Auhor(s) Naalie Ciarocco Insiuion Monmouh Universiy This aciviy can be used as pracice afer sudens have learned how o hand calculae a -es for dependen means. Keywords: -es for ependen Means; Hand Calculaion Brief escripion: Auhor Conac Informaion: Addiional Informaion: nciarocc@monmouh.edu TeachPsychScience.org is made possible wih gran suppor from he Associaion for Psychological Science (APS) Fund for Teaching and Public Undersanding of Psychological Science o he sie creaors Gary Lewandowski, Naalie Ciarocco, and avid Srohmez. All maerials on his sie have been subjeced o a peer review process. We welcome addiional resources ( 010 by Naalie J. Ciarocco. All Righs Reserved. This maerial may be used for noncommercial educaional purposes. All oher uses require he wrien consen of he auhors.

2 Insrucors: Insrucors should assign his problem o sudens as in-class pracice or homework afer sudens have learned how o calculae a -es for dependen means and es for significance. The aciviy leads sudens hrough deermining he ype of saisical analysis o use, he hypoheses, calculaing he -raio and effec size (if appropriae), making a decision abou he null hypohesis and summarizing he resuls. An answer key is included.

3 Pracice: -es A researcher is ineresed in he effecs of wo new drugs, rug A and rug B, on learning. She has a group of 5 people ake rug A and hen work on a learning ask. One monh laer, he same 5 people ake rug B and hen work on he same learning ask as before. The number of errors made on he learning ask afer aking each drug is recorded below. Using an alpha of.01, es for a difference beween he groups. Paricipan rug A rug B Which ype of es will you use? Suppor your answer.. Sae H 0 and H 1.. Is his a one-ailed or wo ailed es? Why? 4. Wha are he df associaed wih his es? 5. Wha is/are he criical value(s) one should use o es he researcher s hypohesis a he.05 level? 6. Calculae he -raio. Be sure o show all of your work. 7. Make a decision abou he null hypohesis and suppor your decision. 8. Calculae he effec size, if applicable, and wha effec size ells us. 9. Give a summary saemen abou he resuls. Think abou he decision on he null, he group means and effec size (when applicable).

4 ANSWERS Pracice: -es A researcher is ineresed in he effecs of wo new drugs, rug A and rug B, on learning. She has a group of 5 people ake rug A and hen work on a learning ask. One monh laer, he same 5 people ake rug B and hen work on he same learning ask as before. The number of errors made on he learning ask afer aking each drug is recorded below. Using an alpha of.01, es for a difference beween he groups. Paricipan rug A rug B Which ype of es will you use? Suppor your answer. A -es for dependen means should be used. This is a repeaed measures design and herefore he means for each group are dependen. (The resuls of rug A on learning are mached o he resuls of rug B for each paricipan.). Sae H 0 and H 1. Null: There is no difference beween errors made in he learning ask when aking rug A compared o rug B. Alernaive: There is a difference beween errors made in he learning ask when aking rug A compared o rug B.. Is his a one-ailed or wo ailed es? Why? The alernaive hypohesis is non-direcional herefore a wo-ail es should be conduced. 4. Wha are he df associaed wih his es? df N Wha is/are he criical value(s) one should use o es he researcher s hypohesis? Calculae he -raio. Be sure o show all of your work. X 1 X M ( M ) X 1 0 X ( M ) 4 N 1 5 N 5 M.00 M M.00

5 S ( Μ ) Ν 1 S S S M 1 S Ν Make a decision abou he null hypohesis and suppor your decision. One should fail o rejec he null hypohesis as he calculaed -raio is no equal o or higher han he criical value of. The group means are he same. 8. Calculae he effec size, if applicable, and wha effec size ells us. The effec size should no be calculaed because here is no a significan difference beween group means. 9. Give a summary saemen abou he resuls. Think abou he decision on he null, he group means and effec size (when applicable). There is no significan difference beween rug A and rug B on he number of errors made on he learning ask. The mean number of errors made while aking rug A (M 6.00) is he same as he mean number of errors made when aking rug B (M.00).