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Manipulation checks are often advisable in experimental studies, yet they rarely appear in practice. This lack of usage may stem from fears of distorting treatment effects and uncertainty regarding which type to use (e.g., instructional manipulation checks [IMCs] or assessments of whether stimuli alter a latent independent variable of interest). Here, we first categorize the main variants and argue that factual manipulation checks (FMCs)-that is, objective questions about key elements of the experiment-can identify individual-level attentiveness to experimental information and, as a consequence, better enable researchers to diagnose experimental findings. We then find, through four replication studies, little evidence that FMC placement affects treatment effects, and that placing FMCs immediately post-outcome does not attenuate FMC passage rates. Additionally, FMC and IMC passage rates are only weakly related, suggesting that each technique identifies different sets of attentive subjects. Thus, unlike other methods, FMCs can confirm attentiveness to experimental protocols.

A symmetry analysis based upon the structure of simple molecules and their anticipated intermolecular interactions can lead to successful predictions of molecular packing and crystal symmetry. As a demonstration of these ideas an in-depth study of the oxalamide functionality as a persistent hydrogen bonding unit is presented. The synthesis and structural characterization of a series oxalamide dicarboxylic acids is presented and the structures compared with the analogous urea compounds. Both the urea and oxalamide dicarboxylic acids form designed two-dimensional hydrogen-bonded -networks with a significant degree of reliability. The urea designs are quite reliable when there is a molecular 2-fold axis, but competing hydrogen bond patterns are found when less symmetrical molecules are studied. The oxalamide design based on inversion centers is also quite reliable, with the designed layer structure found in most cases.

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