{"@context":{"@language":"en","@vocab":"https://schema.org/","citeAs":"cr:citeAs","column":"cr:column","conformsTo":"dct:conformsTo","cr":"http://mlcommons.org/croissant/","rai":"http://mlcommons.org/croissant/RAI/","data":{"@id":"cr:data","@type":"@json"},"dataType":{"@id":"cr:dataType","@type":"@vocab"},"dct":"http://purl.org/dc/terms/","examples":{"@id":"cr:examples","@type":"@json"},"extract":"cr:extract","field":"cr:field","fileProperty":"cr:fileProperty","fileObject":"cr:fileObject","fileSet":"cr:fileSet","format":"cr:format","includes":"cr:includes","isLiveDataset":"cr:isLiveDataset","jsonPath":"cr:jsonPath","key":"cr:key","md5":"cr:md5","parentField":"cr:parentField","path":"cr:path","recordSet":"cr:recordSet","references":"cr:references","regex":"cr:regex","repeated":"cr:repeated","replace":"cr:replace","sc":"https://schema.org/","separator":"cr:separator","source":"cr:source","subField":"cr:subField","transform":"cr:transform","wd":"https://www.wikidata.org/wiki/"},"@type":"sc:Dataset","conformsTo":"http://mlcommons.org/croissant/1.0","name":"A Year of Desirable Difficulties: The Impact of Interleaving Math Practice in Nigeria","url":"https://doi.org/10.7910/DVN/BBS0SH","creator":[{"@type":"Person","givenName":"Guthrie","familyName":"Gray-Lobe","affiliation":{"@type":"Organization","name":"University of Chicago"},"sameAs":"https://orcid.org/0000-0002-5276-5860","@id":"https://orcid.org/0000-0002-5276-5860","identifier":"https://orcid.org/0000-0002-5276-5860","name":"Gray-Lobe, Guthrie"}],"description":"This paper tests whether increasing students’ exposure to “desirable difficulties” improves learning in real classrooms. In a year-long field experiment in Nigerian primary schools, interleaved math practice raised short-term test performance by 0.28 standard deviations but had no effect on cumulative end-of-year assessments. Gains were concentrated among lower-achieving students, while higher-achieving students saw little or no benefit. The results suggest that strategies that make learning more effortful can boost short-term mastery but may not produce durable improvements, highlighting the limits of applying laboratory-based cognitive interventions at scale.","keywords":["Social Sciences"],"license":"http://creativecommons.org/publicdomain/zero/1.0","datePublished":"2026-03-31","dateModified":"2026-03-31","includedInDataCatalog":{"@type":"DataCatalog","name":"Harvard Dataverse","url":"https://dataverse.harvard.edu"},"publisher":{"@type":"Organization","name":"Harvard Dataverse"},"version":"1.0","citeAs":"@data{DVN/BBS0SH_2026,author = {Gray-Lobe, Guthrie},publisher = {Harvard Dataverse},title = {A Year of Desirable Difficulties: The Impact of Interleaving Math Practice in Nigeria},year = {2026},url = {https://doi.org/10.7910/DVN/BBS0SH}}","citation":[{"@type":"CreativeWork","name":"Michael Kremer, Guthrie Gray-Lobe, Joost de Laat, and Lotte van der Haar, \"A Year of Desirable Difficulties: The Impact of Interleaving Math Practice in Nigeria,\" NBER Working Paper 31853 (2023), https://doi.org/10.3386/w31853.","@id":"https://www.nber.org/papers/w31853","identifier":"https://www.nber.org/papers/w31853","url":"https://www.nber.org/papers/w31853"}],"distribution":[{"@type":"cr:FileObject","@id":"difficulties_replication_package.zip","name":"difficulties_replication_package.zip","encodingFormat":"application/zip","md5":"76e866ad6da3bd28044a9da230d1c476","contentSize":"1052760","description":"","contentUrl":"https://dataverse.harvard.edu/api/access/datafile/13628543"}]}