Where does influence collide?

The process by which one person's attitudes, beliefs, or behaviour are changed by the real or implied presence of others. Kelman's 1958 Compliance, identification, and internalization separated three routes this can take: compliance, going along to gain reward or avoid punishment; identification, adopting a position to sustain a valued relationship; and internalization, accepting it because it fits one's own values. The referent is a psychological change inside an individual, judged by whether and why an attitude shifts. It is not a single stray data point in a regression, a person who relays media messages, or a diagram in structural engineering.[1]

Unit

One instance of a person's attitude or behaviour shifting under another's presence

Recovery means

An attitude changed only by compliance can revert once the reward or surveillance is removed

Measured by

Assessed by attitude and behaviour change in experiments and surveys, and by which of the three processes best fits how the change persists

A single observation whose inclusion substantially changes the estimated coefficients or fitted values of a regression, so that deleting it would move the model by a large amount. Cook's 1977 Detection of Influential Observation in Linear Regression introduced Cook's distance, a measure of how far the fitted values shift when one case is left out, combining that case's leverage with the size of its residual. The referent is a property of one row of data relative to a model, scaled by that distance. It is not a change of mind in a person, a relayer of opinion, or a line drawn for moving loads.[2]

Unit

One observation, scored by how much omitting it moves the fitted regression

Recovery means

Not applicable

Measured by

Quantified by Cook's distance, leverage (hat values), and deletion diagnostics such as DFFITS and DFBETAS

The sway that certain well-connected individuals, opinion leaders, hold over the choices and views of the people around them, standing between mass media and the wider public. Katz and Lazarsfeld's 1955 book Personal Influence set out the two-step flow: messages often reach the public not directly but through these leaders, who filter and pass them on in everyday talk. The referent is interpersonal reach across a social network, traced through who informs and persuades whom. It is not an internal attitude process, a diagnostic on one data point, or a graph in engineering.[3]

Unit

One opinion leader's reach over others' decisions in a given domain

Recovery means

Not applicable

Measured by

Traced by self-report and network surveys of who is asked for advice, sociometric ties, and word-of-mouth reach

A graph that shows how one chosen structural quantity, such as a support reaction, a shear, or a bending moment at a fixed point, varies as a single unit load moves step by step across a structure. Standard structural analysis texts, such as Hibbeler's Structural Analysis, present the influence line as the tool for finding where a moving load must sit to produce the largest response, drawing on the Müller-Breslau principle. The referent is a curve in load position, read to place traffic or crane loads for the worst case. It shares nothing with an attitude change, a regression diagnostic, or an opinion leader beyond the word.[4]

Unit

One response quantity plotted against the position of a moving unit load

Recovery means

Not applicable

Measured by

Constructed by moving a unit load across the span, or by the Müller-Breslau principle, and read to position real loads for maximum effect

In literary theory, influence refers to the anxiety of influence, Bloom's account of poets struggling against strong precursors by creatively misreading them. This meaning comes from Bloom (1973) in The anxiety of influence: a theory of poetry.[5]

Unit

Recovery means

Measured by