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Canonical CRISPR-Cas9 genome editing technique has profoundly impacted the fields of plant biology, biotechnology, and crop improvement. Since non-homologous end joining (NHEJ) is usually considered to generate random indels, its high efficiency mutation is generally not pertinent to precise editing. Homology-directed repair (HDR) can mediate precise editing with supplied donor DNA, but it suffers from extreme low efficiency in higher plants. Therefore, precision editing in plants will be facilitated by the ability to predict NHEJ repair outcome and to improve HDR efficiency. Here, we report that NHEJ-mediated single nucleotide insertion at different rice genes is predictable based on DNA sequences at the target loci. Three mutation prediction tools (inDelphi, FORECasT, and SPROUT) have been validated in the rice plant system. We also evaluated the chimeric guide RNA (cgRNA) and Cas9-Retron precISe Parallel Editing via homologY (CRISPEY) strategies to facilitate donor template supply for improving HDR efficiency in Nicotiana benthamiana and rice. However, neither cgRNA nor CRISPEY improved plant HDR editing efficiency in this study. Interestingly, our data indicate that tethering of 200–250 nucleotides long sequence to either 5′ or 3′ ends of guide RNA did not significantly affect Cas9 cleavage activity. 

The purpose of this working group is to continue to bring together scholars with an interest in examining the use of and access to large-scale quantitative tools used to measure student- and teacher-related outcomes in mathematics education. The working group session will focus on (1) updating the workgroup on the progress made since the first working group at PME-NA in Tucson, Arizona, specifically focusing on the outcomes of the Validity Evidence for Measurement in Mathematics Education conference that took place in April, 2017, in San Antonio, (2) continued development of a document of available tools and their associated validity evidence, and (3) identification of potential follow-up activities to continue this work. The efforts of the group will be summarized and extended through both social media tools and online collaboration tools to further promote this work. 

As early as Descartes (1637/1970), logic and reason have been positioned as tools for individuals to advance their own understanding. By contrast, argumentation is an interactive, social exercise used for persuasion, collective cognition, and to advance shared knowledge (Mercier & Sperber, 2011, 2017). When one advances an argument, subjects it to the tests and challenges of others, and responds to questions and counterarguments, one’s thinking improves (Mercier & Sperber, 2017). Through argumentation, groups produce correct solutions more often than individuals (Moshman & Geil, 1998) and individual accuracy improves as well (Castelain, Girotto, Jamet, & Mercier, 2016). Since it was formally introduced by Kane (1990, 1992), the argument-based approach to validation has been promoted in the field of educational and psychological measurement as the preferred method for validating interpretations and uses of test scores (AERA, APA, & NCME, 2014; Kane, 2013; Schilling & Hill, 2007). Scholars continue to debate the best approaches for developing and supporting validity arguments, however (for examples, see Brennan, 2013; Kane, 2007).