{"doi":"10.18637/jss.v082.i13","title":"<b>lmerTest</b> Package: Tests in Linear Mixed Effects Models","abstract":"One of the frequent questions by users of the mixed model function lmer of the lme4 package has been: How can I get p values for the F and t tests for objects returned by lmer? The lmerTest package extends the 'lmerMod' class of the lme4 package, by overloading the anova and summary functions by providing p values for tests for fixed effects. We have implemented the Satterthwaite's method for approximating degrees of freedom for the t and F tests. We have also implemented the construction of Type I - III ANOVA tables. Furthermore, one may also obtain the summary as well as the anova table using the Kenward-Roger approximation for denominator degrees of freedom (based on the KRmodcomp function from the pbkrtest package). Some other convenient mixed model analysis tools such as a step method, that performs backward elimination of nonsignificant effects - both random and fixed, calculation of population means and multiple comparison tests together with plot facilities are provided by the package as well.","journal":"Journal of Statistical Software","year":2017,"id":6869,"datarank":16.97481438910954,"base_score":10.032408332602968,"endowment":10.032408332602968,"self_citation_contribution":1.5048612498904455,"citation_network_contribution":15.469953139219093,"self_endowment_contribution":1.5048612498904455,"citer_contribution":15.469953139219093,"corpus_percentile":97.6,"corpus_rank":283,"citation_count":22751,"citer_count":200,"citers_with_citation_signal":200,"citers_with_endowment":200,"datacite_reuse_total":0,"is_dataset":false,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2017-01-01","authors":[{"id":63119,"name":"Per B. Brockhoff","orcid":"0000-0002-1432-7229","position":1,"is_corresponding":false},{"id":63120,"name":"Rune H. B. Christensen","orcid":null,"position":2,"is_corresponding":false},{"id":63121,"name":"Rune Haubo Bojesen Christensen","orcid":"0000-0002-4494-3399","position":3,"is_corresponding":false},{"id":63118,"name":"Alexandra Kuznetsova","orcid":"0000-0001-6458-2597","position":0,"is_corresponding":true}],"reference_count":27,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-03-01T18:20:47.508186Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}