Copula + Adjective

An a-posteriori power analysis for the generalizability of results


  • Jorge Aguilar-Sánchez University of Dayton



Power, Effect Size, Spanish copula, Sample size


Researchers sometimes, unknowingly, exclude the existence of the phenomenon in the population under study to develop investigations that try to explain discrepancies observed in the literature. Explanations justifying each study are based on theories; or conjecture related to specific independent variables and how researchers disagree with the construct proposed originally. These disagreements create variants of the original study, but not proper replications of it. This practice produces what Ottenbacher (1996: 275) called 'a contradictory research literature, apparently dynamic, but failing to resolve uncertainties; therefore, failing to establish statistical consensus'. To resolve these uncertainties, this paper addresses the concerns that arise by not reporting two statistics: power and effect size. Power calculations were conducted for the studies on copula choice in bilingual Spanish. Results show that studies have a low power due to decisions that were made during their design, or due to the aggregation of naturally independent data. due to the aggregation of naturally independent data.

Author Biography

  • Jorge Aguilar-Sánchez, University of Dayton

    Jorge Aguilar-Sánchez is Assistant Professor of Spanish Linguistics in the Department of Global Languages and Cultures, University of Dayton, Dayton, OH, USA.


Aguilar-Sánchez, J. (2007). The use of Spanish Ser and Estar + adjectives: A sociolinguistic pilot study on the oral Spanish of Costa Rica. Paper presented at the 5th Hawaii Annual International Conference on the Arts and the Humanities, Hawaii.

Aguilar-Sánchez, J. (2009). Syntactic Variation: The case of copula choice in the Spanish of Limón, Costa Rica. (Doctoral thesis), Indiana University, Bloomington, IN.

Aguilar-Sánchez, J. (2012). Formal instruction and language contact in language variation: The case of Ser and Estar + Adjective in the Spanishes of Limón, Costa Rica. In K. Geeslin and M. Díaz-Campos (Eds), Selected Proceedings of the 14th Hispanic Linguistic Symposium, 9–25. Sumerville, MA: Cascadilla Proceedings Project.

Aguilar-Sánchez, J. (2014). Replicability of (Socio)Linguistics studies. Journal of Research Design and Statistics in Linguistics and Communication Science 1 (1), 5–25.

Aguilar-Sánchez, J. (2017). Research Design Issues and Syntactic Variation: Copula choice in Limón, Costa Rica. Balti: Lambert Academic Publishing (LAP).

Aguilar-Sanchez, J. (forthcoming). Looking Back to Move Forward: Design Issues and Best Practices in the Study of Language Variation and Change.

Algina, J., and Olejnik, S. (2000). Determining sample size for accurate estimation of the squared multiple correlation coefficient. Multivariate Behavioral Research 35 (1), 119–137.

Beck, C. T. (1994). Achieving statistical power through research design sensitivity. Journal of Advanced Nursing 20 (5), 912–916.

Cohen, J. (1969). Statistical Power Analysis for the Behavioral Sciences. New York,: Academic Press.

Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Hillsdale, NJ: L. Erlbaum Associates.

Cohen, J. (1992a). A power primer. Psychological Bulletin 112 (1), 155–159.

Cohen, J. (1992b). Statistical Power Analysis. Current Directions in Psychological Science 1 (3), 98–101.

Díaz-Campos, M. and Geeslin, K. L. (2011). Copula use in the Spanish of Venezuela: Is the pattern indicative of stable variation or an ongoing change? Spanish in Context 8 (1), 73–94.

Geeslin, K. L. and Díaz-Campos, M. (2005). Is the extension of estar a change in progress or a stable change? A combined analysis of sociolinguistic and discourse factors in Spanish. Paper presented at the Department of Spanish and Portuguese: Linguistic Brown Bag Series, Indiana University.

Gelman, A. and Hill, J. (2007). Data Analysis using Regression and Multilevel/hierarchical Models. Cambridge and New York: Cambridge University Press.

Gries, S. T. (2015). The most under-used statistical method in corpus linguistics: Multi-level (and mixed-effects) models. Corpora 10 (1), 95–125.

Grissom, R. J. and Kim, J. J. (2005). Effect Sizes for Research: A Broad Practical Approach. Mahwah, NJ: Lawrence Erlbaum.

Gutiérrez, M. (1994). La influencia de ‘los de abajo’ en tres procesos de cambio lingüístico en el español de Morelia, Michoacán. Language Problems and Langauge Planning 18 (3), 257–269.

Holden, J. E., Kelley, K., and Agarwal, R. (2008). Analyzing change: A primer on multilevel models with applications to nephrology. American Journal of Nephrology 28, 792–801.

Johnson, D. E. (2014). Progress in regression: Why sociolinguistic data calls for mixed-effect models. [Self published manuscript]. Retrieved on 12 May 2015 from

Kelley, K. and Maxwell, S. E. (2008). Sample size planning for multiple regression: Power and accuracy for omnibus and targeted effects. In P. Alasuutari, L. Bickman, and J. Brannen (Eds), The SAGE Handbook of Social Research Methods, 166–192. Newbury Park, CA: SAGE.

Kelley, K., Maxwell, S. E., and Rausch, J. R. (2003). Obtaining power or obtaining precision. Evaluation & the Health Professions 26 (3), 258–287.

Kraemer, H. C. and Thiemann, S. (1987). How many Subjects?: Statistical Power Analysis in Research. Newbury Park, CA: Sage Publications.

Leon, A. C. (2004). Sample-size requirements for comparisons of two groups on repeated observations of a binary outcome. Eval Health Prof 27 (1), 34–44.

Lipsey, M. W. (1990). Design Sensitivity: Statistical Power for Experimental Research. Newbury Park, CA: Sage Publications.

Morley, S. G. (1925). Modern uses of Ser and Estar. PMLA: Publications of the Modern Language Association of America 40 (2), 450–489.

Murphy, K. R. and Myors, B. (1998). Statistical Power Analysis: A Simple and General Model for Traditional and Modern Hypothesis Tests. Mahwah, NJ: L. Erlbaum Associates.

Onwuegbuzie, A. J. and Leech, N. L. (2004). Post hoc power: A concept whosetime has come. Understanding Statistics 3 (4), 201–230.

Ortíz-López, L. A. (2000). Extensión de estar en contextos de ser en el español de Puerto Rico: ¿evolución interna o contacto de lenguas? Boletín de la Académia Puertorriqueña de la Lengua Española, 98–118.

Osborne, J. W. (2015). Best Practices in Logistic Regression. Los Angeles, CA: SAGE.

Ottenbacher, K. J. (1996). The power of replications and replications of power. The American Statistician 50 (3), 271–275.

Rosenthal, R. (1994). Parametric measures of effect size. In H. M. Cooper and L. V. Hedges (Eds), The Handbook of Research Synthesis, 231–244. New York: Russell Sage Foundation.

Rossi, J. S. (1990). Statistical power of psychological research: What have we gained in 20 years? Journal of Consulting and Clinical Psychology 58 (5), 646–656.

Salazar, M. L. (2007). Está muy diferente a como era antes: Ser and Estar + adjective in New Mexico Spanish. In K. Potowski and R. Cameron (Eds), Spanish in Contact: Policy, Social and Linguistic Inquiries, 345–355. Amsterdam: John Benjamins Publishing Company.

Schmitt, C. and Miller, K. (2007). Making discourse-dependent decisions: The case of the copulas ser and estar in Spanish. Lingua 117 (11), 1907–1929.

Schmitz, S., Cherny, S. S., and Fulker, D. W. (1998). Increase in power through multivariate analyses. Behavior Genetics 28 (5), 357–363.

Sedlmeier, P. and Gigerenzer, G. (1989). Do studies of statistical power have an effect on the power of studies? Psychological Bulletin 105 (2), 309–316.

Silva-Corvalán, C. (1986). Bilingualism and language change: The extension of estar in Los Angeles Spanish. Language: Journal of the Linguistic Society of America 62 (3), 587–608.

Silva-Corvalán, C. (1994). Language Contact and Change: Spanish in Los Angeles. Oxford: Clarendon.

Silva-Corvalán, C. (2001). Sociolingüística y pragmática del español. Washington, DC: Georgetown University Press.

Sprinthall, R. C. (2003). Basic Statistical Analysis (7th ed.). Boston, MA: Allyn and Bacon.

Tversky, A. and Kahneman, D. (1971). Belief in the law of small numbers. Psychological Bulletin 76 (2): 105–110.

Vaske, J. J., Gliner, J. A., and Morgan, G. A. (2002). Communicating judgments about practical significance: Effect size, confidence intervals and odds ratios. Human Dimensions of Wildlife 7 (4), 287–300.

Wilkinson, L. and The American Psychological Association Task Force. (1999). Statistical methods in psychology journals: Guidelines and explanations. American Psychologist 54 (8), 594–604.

Zodpey, S. P. (2004). Sample size and power analysis in medical research. Indian Journal of Dermatology, Venereology and Leprology 70 (2), 123–128.






How to Cite

Aguilar-Sánchez, J. (2018). Copula + Adjective: An a-posteriori power analysis for the generalizability of results. Journal of Research Design and Statistics in Linguistics and Communication Science, 4(2), 91-123.