Class 3 Between Group Designs, Expo Facto Designs, Status Variable Chapters HWK 7 ( ),10 ( , 243-4) 12(308) ANOVA PDF

Between Group Design Therapy Outcome Research Purpose Independent Variable Assignment to Groups Treatment Delivery Participant Selection Control Group 2

Between Group Design Therapy Outcome Research Purpose Compare treatment groups under tightly controlled conditions Independent Variable Highly specified; manipulated; categorical Assignment to Groups Random; stratified; each participant only 1 treatment Treatment Delivery Closely monitored Participants Highly selective Control Group No-treatment/Placebo, or Other Active Treatment 3

Within Group Design Therapy Outcome Research Purpose Compare treatments under tightly controlled conditions Independent Variable Highly specified; manipulated; categorical Assignment to GroupsRandom to the time each treatment is delivered; each participant all treatments Treatment Delivery Closely monitored Participants Highly selective Control Group Active Treatments 4

Does loud noises affect short term memory? – Within Subjects Variable. 5

Advantages of Pre-Test Select participants; describe groups Use as a covariate when comparing post- test means Comparing gain scoresis not recommended (p.153) Compare drop-outs and completers in initial severity Use as post-test for early terminators in “intent to treat” analyses 6

Treatment Study: Question 5 Research Design Independent Variables Dependent Variables Participants 7

Treatment Study: Question 5 Research Design Experimental, BW-groups, posttest, factorial Independent Variables (Main Effects) 8

Treatment Study: Question 5 Research Design Experimental, BW-groups, posttest, factorial Independent Variables (Main Effects) Treatments: Cult. Infused vs. Standard Therapist Ethnicity: Latino/a vs. White In this study, is ethnicity a true IV or a status variable? Why? 9

Study Description A study examined the effectiveness of two treatments (culturally infused treatment vs. treatment as usual) to enhance the parenting skills of 100 mothers of Mexican descent of a age child. The treatments were delivered by either a Latino therapist (half of the sample) or a White therapist (to the other half). Parents were randomly assigned to the type of treatment and the therapist’s ethnicity conditions. 10

Treatment Study: Question 5 Dependent Variable(s) Scores Parenting Skills – Continuous Participants 100 Moms of Mexican descent With a child years old 11

Treatment Study: Question 5(b) Potential research questions regarding treatment effectiveness Question 1: Question 2: Question 3: 12

Treatment Study: Question 5(b) Potential research questions regarding treatment effectiveness Question 1:Main Effect Treatment Group Question 2:Main Effect Therapist Ethnicity Question 3: Moderation Effect Treatment X Therapist 13

Question 1 Do parents in the Culturally Infused Treatment (T1) obtain higher post-test scores in parenting skills than parents in the Treatment as Usual (T2) ? 14 Treatment 1Treatment 2 Mean = 7.9Mean = 5.2

Question 2 Do parents who had a Latino Therapist obtain higher post-test scores in parenting skills than parents who had a White Therapist 15 Latina/o Th Anglo Th Mean = 6.5Mean = 6.4

Question 3 Moderation Does Therapist ethnicity moderate the association of type of treatment to parenting skills scores? Among participants with Latino/a TH: Among participants with Anglo TH: 16 Treatment 1 Infused Treatment 2 Usual Latina/o Anglo

2X2 ANOVA with Moderation Covariate Pre-Test Parenting Scale Moderator:Therapist Ethnicity IVs DV Post Test Parental Skills Scales F statistic Treatment 2 Means Treat. I vs. Treat 2 Main Effect * Therapist Ethnicity 2 Means Anglo vs. Latino/a Th Main Effect ns Treatment X Therapist Ethnicity 4 Means Th Anglo: T1 vs. T2 Th Hispanic: T1 vs. T2 Interaction Effect ? 17

Question 3 Moderation Does Therapist ethnicity moderate the association of type of treatment to parenting skills scores? Among participants with Latino/a TH: do parents in T1 obtain higher parenting scores than those in T2 Among participants with Anglo TH: do parents in T1 obtain higher parenting scores than those in T2 18 Treatment 1 Infused Treatment 2 Usual Latina/o Mean = 7.4*Mean = 6.1 Anglo Mean = 7.0*Mean = 6.4

2X2 ANOVA with Moderation DVPost-Test Parenting Scale Covariate Pre-Test Parenting Scale IV DV Post Test Parental Skills Scales F statistic Treatment 2 Means Treat. I* vs. Treat 2 Main Effect * Therapist Ethnicity 2 Means Anglo vs. Latino/a Th Main Effect ns Treatment X Therapist Ethnicity 4 Means Th Anglo: T1* vs. T2 Th Hispanic: T1* vs. T2 Interaction Effect ns 19

Table 1 Main Effects Means Post-Test Parenting Scale Effects Post-Test Parenting Scale Mean Mean F value Main: Treatment Infused Treatm. 7.9* Usual Treatm. 6.2 *p<.05 Main Therapist Ethnicity Hispanic Th. 6.5 Anglo Th. 6.4 NS Interaction Treat X Th Eth Infused Treat Latino/a 7.4* Anglo 7.0* Infused Treat NS Possible range of scores for parenting Scale = 1 to 10 20

Results showed A main effect for treatment No main effect for therapist Therapist ethnicity did not moderate the effect of treatment on parenting skills for the White therapists, Infused T>Usual T for Latino/a therapists, Infused T>Usual T 21

Does Therapist Ethnicity moderate the treatment difference in parental skills? ?? 1. Does the culturally infused vs. the usual treatment produce a higher mean score in mom’s post-test parenting skills when administered by the Anglo Therapists? Yes vs. 6.4 *p < Does the culturally infused vs. the usual treatment produce a higher mean score in mom’s post-test parenting skills when administered by the Latina/o Therapists Yes – 7.4 vs. 6.1 *p <.05 22

Does Therapist Ethnicity moderate the treatment difference in parental skills? NO Therapists’ ethnicity did not matter: with both types of therapists, mothers in culturally infused treatment obtained higher post-test parental skills scores than mothers in usual treatment. 23

Conclusion If interaction effect(s) is present, related main effect(s) is (are) not interpreted. In this case, should we interpret the treatment main effect? 24

Conclusion If interaction effect(s) is present, related main effect(s) is (are) not interpreted. In this case, should we interpret the treatment main effect? Yes, because there is no moderation effect for Therapist ethnicity 25

Table 1A Main & Interaction Effects Means Post-Test Parenting Scale Effects Post-Test Parenting Scale Mean Mean F value Main: Treatment Infused Treatm. 7.9* Usual Treatm. 6.2 *p<.05 Main Therapist Ethnicity Hispanic Th. 6.5 Anglo Th. 6.4 NS Interaction Treat X Th Eth Infused Treat Latino/a 7.4 ns Anglo 7.0* Usual Treat *p<.05 Possible range of scores for parenting Scale = 1 to 10 26

Conclusion Regarding Table 1A, should we interpret the treatment main effect? NO, because there is a moderation effect for Therapist ethnicity Results show that for Latino Th – no effect for treatment type For Anglo Th- Infused T >Usual T 27

Second Study Question 6 Research Design Independent Variables Dependent Variables Participants 28

Second Study Question 6 Research Design Non-experimental - Association Factorial Between Groups 29

Second Study Q. 6 Independent Variables Moms Place of Birth Target Child’s Gender US Mexico Boys Girl 30 Participants 100 Mothers year olds 50 daughters 50 sons Dependent Variables Self Reported Parenting Skills Scale -- SRPSS

Research Questions DV- SR Parenting Scale #6 Main Effects DV- Pre-test SR Parental Skills Scale F statistic Main Effect Main Effect Moderation effects 31

Research Questions DV- SR Parenting Scale #6 Main Effects DV- Pre-test SR Parental Skills Scale F statistic Mom Place of Birth Mexico vs. US (Mexico + USA) Main Effect Child Gender Boys vs. Girls (Boys + Girls) Main Effect Which we want to examine as moderator? 32

Research Questions Study Question # 6 1. Main Effect Place of birth: Do moms born in USA obtain higher scores in pre-test parenting skills than moms born in Mexico? 2. Main Effect Child’s Gender: Do moms of boys obtain higher scores in pre-test parenting skills than moms of girls? 3. Interaction Effect: Moderator?? 33

Main Effects Q. 6C-1 & 6C-2 Place of Birth: It is hypothesized that: Target Child’s Gender It is hypothesized that: 34

Main Effects Place of Birth: (acculturation) It is hypothesized that mothers born in the US will obtain higher mean score in the parenting skills measure than mothers born in Mexico Child’s Gender (gender role rearing beliefs) It is hypothesized that mothers of boys will obtain a higher mean score in the parenting skills measure than mothers of girls 35

Table 4: 2X2 ANOVA Main Effects Moderator: Mom P Birth IVs DV- Pre-test SR Parental Skills Scale F statistic Mom Place of Birth Mexico vs. US (Mexico + USA) Main Effect Child Gender Boys vs. Girls (Boys + Girls) Main Effect* Child Gender X Mom P Birth 36

Moderation Effect – Q6 D1 & 2 Mother’s Place of Birth will moderate the association of child’s gender to pre-test parenting skills so that: Among mother’s born in US Among mother’s born in Mexico 37

Moderation Effect Q6 D1 & 2 Mother’s Place of Birth will moderate the association of child’s gender to pre-test parenting skills so that: Among Mothers born in US, there will be no difference in the mean score of the parenting skills scale among mothers of boys compared to mothers of girls Among mothers born in Mexico, mothers of boys will obtain higher mean scores in the parenting skills scale than mothers of girls 38

IV DV- Pre-test SR Parental Skills ScaleF statistic Mom Place of Birth Mexico vs. US ( regardless offspring gender ) Main Effect Child Gender Boys vs. Girls (regardless Mom place birth) Main Effect Child Gender x Mom P. Birth Mom Mexico: Boys vs. Girl s Mom US : Boys vs. Girls Mom’s birth place as moderator Table 4: 2X2 ANOVA with Moderation Moderator: Moms P. of Birth 39

Table 1 Parenting Skills Main Effect: Mom’s Country of Birth and Child’s Gender Main Effects Parenting Scale Mean Mean F statistic Mom Birth Country Mexico 2.8 USA ns 3.0 p>.05 Target Child’s Gender Mom of Girls 2.4 Mom of Boys 3.5* *p<.05 Possible range of scores for parenting Scale = 1 to 5 40

Result Main Effects: Place of Birth Question #6 Table 5 Do moms born in USA obtain higher scores in parenting skills than moms born in Mexico? Answer: No 2.8 vs. 2.9 P>.05 41

Results Main Effects: Child’s Gender Question #6 Table 5 Do moms of boys obtain higher scores in parenting skills than moms of girls? Answer: Yes, 3.3 vs. 2.3 p<.05 42

IV DV- Pre-test SR Parental Skills ScaleF statistic Mom Place of Birth Mexico vs. US (Mexico + USA) Main Effect NS Child Gender Boys vs. Girls (Boys + Girls) Main Effect* * p<.05 Child Gender x Mom P. Birth M Born Mexico: Boys vs. Girl s M Born US : Boys vs. Girls Mom’s birth place as moderator Table 4: 2X2 ANOVA with Moderation DV- SR Parenting Scale – Moderator Mom place of birth 43

Interaction Effects Study Q. #6: Moderator: Mom’s Place Birth Does mom’s place of birth moderate (make a difference in) the association of child’s gender to mom’s parenting skills: Mothers born in Mexico we may expect that: Mothers born in US we may expect that 44

Interaction Effects Study Q. #6: Moderator: Mom’s Place Birth Does mom’s place of birth moderate (make a difference in) the association of child’s gender to mom’s parenting skills: Mothers born in Mexico we may expect that: Mother of boys will score higher in the SRPSS than mother of girls Mothers born in US we may expect that 45

Interaction Effects Study Q. #6: Moderator: Mom’s Place Birth Does mom’s place of birth moderate (make a difference in) the association of child’s gender to mom’s parenting skills: Mothers born in Mexico we may expect that: Mother of boys will score higher in the SRPSS than mother of girls Mothers born in US we may expect that Mother of boys and girls will not differ in in the SRPSS scores 46

Table 2 Moderation Effects Means Parenting Skills Ratings by Child’s Gender Moderator: Mom’s Country of Birth Mom of Girls Mom of Boys Born Mexico * *p<.05 Born USA p>.05 47

Table 1 Parenting Skills Main & Moeration Effect: Moderator: Mom P. of Birth Main Effects Parenting Scale Mean Mean F statistic Mom Birth Country Mexico 2.8 USA 3.0 ns p>.05 Child’s Gender Mom of Girls 2.4 Mom of Boys 3.5* *p<.05 Child Gender x Mom P. Birth Mom Girls Mom Mexico 1.9 Mom US 2.7 Mom of Boys 3.8* 3.1 ns *p<.05 Possible range of scores for parenting Scale = 1 to 5 48

Interaction Effects Study Q. #6: Moderator: Mom’s Place of Birth Does mom’s place of birth moderates the association of child’s gender to parenting skills score? Yes Among Moms born in Mexico, moms of boys obtained higher scores in parenting skills than moms of girls? 3.8* vs. 1.9 p<.05 Among Moms born in USA, moms of boys obtained similar scores in parenting skills than moms of girls? 3.1 vs. 2.5 NS 49

Conclusions Only among Mom’s born in Mexico, moms of boys scored higher in the parenting skills questionnaire than mom’s of girls. Among mom’s born in US no differences in parenting score by target child’s gender Therefore, the main effect for child’s gender applies only to mom’s born in Mexico. Findings support 2 of the 3 hypothesis Is the SR-PSS a valid measures of parenting skills among Latina mothers? 50

Is SR-PSS a valid measures of parenting skills among Latina mothers? The SR-PSS seems to assess endorsement of autonomy in child rearing practices Latina mothers born in Mexico endorse higher levels of autonomy when target child is boy than when it is a girl – consistent with predominant values in Latino culture Latina mothers born in US exhibit similar levels of parenting skills when target child is boy than when it is a girl – Born in US more highly acculturated to US child rearing values. 51

Comparison of Studies Study Question #5Question #6 IVs Both Manipulated CategoricalBoth Status, Categorical DVsContinuous; Parenting SkillsContinuous: Parenting Skills DesignExperimental, factorial, Betw.-GAssociation, factorial, Betw-G Assignmen t Analyses Groups RandomAssigned AnalysisANOVA 2X2 52

Differences in Studies Questions #5 and #6 (1/2) Nature of IVs and DVs # 5 Both Vs are manipulated #6 Both IVs are inherent to participants #5 & #6 IVs are categorical #5 & #6 DVs are continuous Design #5 Experimental factorial #6 Expo-facto factorial 53

Differences Studies in Questions #5 and #6 (2/2) Assignment of participants to conditions, #5 random #6 characteristic inherent to participants Statistical analyses Both: ANOVA with interaction effects Inferences from results #5 Causal vs. #6 Association 54

Survey or Expo- Facto What is the incidence of PTSD among veterans from the IRAQ war: total, by gender and by ethnic group. Is there an association between gender and ethnicity (B H W) and PTSD in veterans from the IRAQ war. Should we expect gender and ethnic differences; why? 55

Survey DesignExpo-Facto Design o Document nature or frequency of a variable o Association of status variable(s) to continuous variable(s) o Descriptive: No theoretical or logical rational needed o Test Hypotheses o Probability samples o More tolerant of convenience samples 56