Where does probe collide?

In computer science, a probe is a single inspection of a slot in a hash table: under open addressing a key that collides is placed, or searched for, by probing a sequence of slots until an empty one or the key is found, so the probe count measures lookup cost. Peterson's 1957 Addressing for random-access storage analysed open addressing and the expected number of probes as a table fills. The referent is an access step in a data structure, quantified by the average probes per operation as a function of load factor, and it has nothing to do with a labelled molecule or an interviewer's follow-up question.[1]

Unit

The number of slot inspections (probes) per lookup or insertion

Recovery means

Not applicable

Measured by

Measured by the expected number of probes per operation as a function of the table's load factor

In molecular biology, a probe is a labelled fragment of nucleic acid (or an antibody) that locates its complementary target by hybridising to it, so a known, tagged sequence is used to detect an unknown one in a blot, array, or tissue section. Gall and Pardue's 1969 Formation and detection of RNA-DNA hybrid molecules in cytological preparations demonstrated in situ hybridisation, using a labelled nucleic acid to reveal where a matching sequence lies. The referent is a tagged detection reagent defined by its complementarity to a target, measured by the signal where it binds, and it is unrelated to a hash-table inspection or a survey follow-up.[2]

Unit

The specific signal produced where the labelled probe binds its target

Recovery means

Not applicable

Measured by

Read by the labelled signal (radioactive, fluorescent, or enzymatic) at the site of hybridisation, against background

In survey and interview methodology, a probe is a neutral follow-up prompt an interviewer uses to clarify, expand, or complete a respondent's answer without leading it, and in cognitive interviewing probes are planned questions that reveal how respondents understand an item. Willis's Cognitive interviewing sets out concurrent and retrospective probing as a tool for diagnosing question problems. The referent is a verbal elicitation technique judged by whether it draws out usable, unbiased information, and it is a distinct construct from a labelled molecule or a hash-table access, sharing only the meaning of reaching in to find something.[3]

Unit

The additional or clarified response elicited by the follow-up prompt

Recovery means

Not applicable

Measured by

Evaluated by the completeness and clarity of the elicited response and by evidence of how the respondent interpreted the item