Visual inspection is a common method of

quality control Quality control (QC) is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as "a part of quality management focused on fulfilling quality requirements". This approach plac ...

data acquisition Data acquisition is the process of sampling signals that measure real-world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer. Data acquisition systems, abbreviated by the ...

, and

data analysis Data analysis is the process of inspecting, Data cleansing, cleansing, Data transformation, transforming, and Data modeling, modeling data with the goal of discovering useful information, informing conclusions, and supporting decision-making. Da ...

. Visual Inspection, used in maintenance of facilities, mean inspection of equipment and structures using either or all of raw human senses such as vision, hearing, touch and smell and/or any non-specialized inspection equipment. Inspections requiring Ultrasonic, X-Ray equipment,

Infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

, etc. are not typically regarded as visual inspection as these Inspection methodologies require specialized equipment, training and certification.

Quality control

A study of the visual inspection of small

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

s found that the modal duration of eye fixations of trained inspectors was about 200 ms. The most accurate inspectors made the fewest eye fixations and were the fastest. When the same chip was judged more than once by an individual inspector the consistency of judgment was very high whereas the consistency between inspectors was somewhat less. Variation by a factor of six in inspection speed led to variation of less than a factor of two in inspection accuracy. Visual inspection had a false positive rate of 2% and a false negative rate of 23%.

Humorous terminology

To do an eyeball search is to look for something specific in a mass of

code In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communicati ...

or data with one's own eyes, as opposed to using some sort of

pattern matching In computer science, pattern matching is the act of checking a given sequence of tokens for the presence of the constituents of some pattern. In contrast to pattern recognition, the match usually must be exact: "either it will or will not be a ...

software like grep or any other automated search tool. Also known as vgrep or ogrep, i.e., "visual/optical grep". See also vdiff. "Eyeballing" is the most common and readily available method of initial data assessment. This method is effective for identifying patterns or anomalies in complex data but can be time-intensive and error-prone. Although low-cost and adaptable, its efficiency and ROI often fall short compared to automated tools, which offer greater scalability and consistency. However, switching from manual visual inspection to automated methods depends on the task's complexity, scale, and the balance between upfront costs and long-term efficiency. Experts in

pattern recognition Pattern recognition is the task of assigning a class to an observation based on patterns extracted from data. While similar, pattern recognition (PR) is not to be confused with pattern machines (PM) which may possess PR capabilities but their p ...

maintain that the "eyeball" technique is still the most effective procedure for searching arbitrary, possibly unknown structures in data. In the military, applying this sort of search to real-world terrain is often referred to as "using the Mark I Eyeball" device (pronounced as Mark One Eyeball), the U.S. military adopting it in 1950s."Contemporary Geodesy" (Proceedings of a Conference Held at the Harvard College Observatory - Smithsonian Astrophysical Observatory, Cambridge, MA, December 1–2, 1958)
P. 68
says: "Now the first type of optical tracking, the most elementary, is that using merely the naked eye — as I heard a Navy man say the other day, 'Mark I eyeball' ". The term is an allusion on military nomenclature, "Mark I" being the first version of a military vehicle or weapon.

References

{{reflist Quality control Data analysis Vision Computer humour Computer jargon Military humor Nondestructive testing