Assessment, Statistics, and Research

  Covariate . A variable that is correlated with a dependent variable in a research study. When a covariate is identified and measured, the value of the dependent variable can be adjusted for the contribution of the covariate during data analysis. Example: If researchers collect information on the variable age in a study about forgiveness and if age is related to forgiveness, then age can be treated as a covariate to identify how people scored on a forgiveness survey after the scores have been adjusted for age. The word adjusted is a key word to look for in reading research that includes a covariate. Procedures that include covariates are ANCOVA and MANCOVA . Cite this post. Sutton, G. W. (2021, January 14). Covariate. Statistics .  https://statistics.suttong.com/2021/01/covariate.html Please subscribe to this blog for updated statistics and measures. Applied Statistics Concepts for Counselors on  AMAZON  or  GOOGLE Creating Surveys on AMAZON    or   GOOGLE  Worldwide Links to Connect

  MANCOVA (Multivariate Analysis of Covariance). A statistical procedure for analyzing results when there are one or more independent variables , two or more dependent variables , and one or more covariates . Basic components of MANCOVA Independent or grouping Variable = 1 or more Dependent or criterion Variable = 2 or more Covariates = 1 or more Overall tests are used to determine significant effects or differences among the grouping variables. An F test indicates significance overall and for specific effects or relationships. A commonly reported measure of effect size is eta squared. A p value reveals the probability of a significant relationship-- one that is not due to chance factors. Applied Statistics Concepts for Counselors on  AMAZON  or  GOOGLE Creating Surveys on AMAZON    or   GOOGLE  Worldwide Links to Connections   Checkout My Website     www.suttong.com    See my Books      AMAZON             GOOGLE STORE   JOIN me on      FACEBOOK     Geoff W. Sutton          TWITTER  

The Narcissistic Personality Inventory - 13 (NPI-13) was developed by Gentile et al. (2013). It is a shortened version of the 40-item NPI. The authors describe trait narcissism as a trait on a continuum with features of "a grandiose sense of self, feelings of entitlement, and a dominant and antagonistic interpersonal style (p. 1120)." Scale and subscales The NPI-13 has three subscales (Cronbach  alpha values in parentheses): Leadership/authority (.66) Grandiose Exhibitionism (.65) Entitlement/ exploitativeness (.51) Total Scale alpha = .73. Psychometric Properties In general, the three NPI scales were significantly positively correlated with grandiose scales from the PNI and NGS, psychological entitlement, and both self-report and interview-based symptom of NPD. All three were also positively related to self-esteem scores," (Gentile et al., 2013, p. 1124). The authors also found positive correlations between the NPI scales and DSM-IV-TR personality disorders of paranoid

  ANCOVA ANCOVA is a procedure like ANOVA except researchers can study the effects of one or more independent variables on a dependent variable after adjusting for other variables, called covariates , which were not a primary focus of the study. The letter C in ANCOVA stands for covariate . There can be several covariates in a study. In testing for differences among groups experiencing different leadership styles, we could study the effects on employee satisfaction after adjusting for a covariate of years of employment. A key word in ANCOVA studies is adjusting . Analysts adjust the scores based on information about the covariate before testing for significant differences. Basic features of an ANCOVA: Independent or grouping Variable = 1 or more Dependent or criterion Variable = 1 Covariates = 1 or more An  F  test indicates significance overall and for specific effects or relationships. A commonly reported measure of effect size is eta squared. A  p  value reveals the probabilit

There are several types of ANOVA procedures. The term ANOVA refers to Analysis of Variance . Variance is a statistical term we will review later. Variance refers to differences, so the ANOVA procedures examine differences in scores among groups of people who complete a survey, a test, or produce a scorable response. For example, an ANOVA can be used to assess the effects of three temperatures on math. The Independent Variable is temperature varies three ways (75, 85, 95 degrees F). The dependent variable is math. The dependent measure of math is a math test. When there is only one independent variable (IV), the ANOVA is called a one-way ANOVA. If there are two IVs the ANOVA is a two-way ANOVA, and so forth. It is rare to go beyond a four-way because the interpretation of interactions is complicated. The ANOVA procedure is usually reported with an F value. The larger the F value, the more likely it is that the differences the researchers found are not due to chance. There may be s

  MANOVA MANOVA is the abbreviation for Multivariate Analysis of Variance . The M stands for multivariate and refers to the presence of more than one dependent variable. A MANOVA may have one or more independent variables and two or more dependent variables. For example, we could examine the effects of different presenters and different forgiveness programs on forgiveness and compassion. Studies with three to four independent variables and three to four dependent variables can be difficult to interpret because many interactions are possible. Independent or grouping Variable = 1 or more Dependent or criterion Variable = 2 or more Overall tests are used to determine significant effects or differences among the grouping variables. An  F  test indicates significance overall and for specific effects or relationships. A commonly reported measure of effect size is eta squared. A  p  value reveals the probability of a significant relationship-- one that is not due to chance factors. Read m