The Search interface element on the home page behaves oddly.
First, when I click the magnifying glass icon without entering anything, I get a Search results page with "DM-09: Search metadata for specific objects of interest" as the page title. (It even appears in the breadcrumbs at the top of the page.) The search results seem to contain pages that have the word "Search" in them. It looks like it's taking the default text ("Search...") from the search UI element and actually performing a search for it. I don't think this is useful. It would make more sense to either not do anything when the user hits the icon with no text in the field, or else take the user to a generic search page without actually starting a search.
When I enter search terms, the results are weird. Since this is the "Research Software Portal," I expect the search feature will allow me to search for research software, and the results will be software packages. Instead, it seems to be pages on the site, and the hits aren't especially relevant. E.g., searching for "use case" returns the "XCSR Requirements" page as the top hit? Searching for "cosmology" returns zero hits. Searching for "MPI" returns one page: "L1-3 SP Operational Components." None of these are particularly helpful results.
IMO, this site search feature should be replaced by a link to the Comprehensive Software Search. (But see also the related thread, "Life Cycle - Available Software.")