Table of Contents

Broken Window Theory

The Broken Window Theory is a criminological theory of the norm-setting and signaling effect of urban disorder and vandalism on additional crime and anti-social behavior. The theory states that maintaining and monitoring urban environments to prevent small crimes such as vandalism, public drinking, and toll-jumping helps to create an atmosphere of order and lawfulness, thereby preventing more serious crimes from happening.

Control Theory

Control Theoryis an interdisciplinary branch of engineering and mathematics that deals with the behavior of dynamical systems with inputs, and how their behavior is modified by feedback. The usual objective of control theory is to control a system, often called the plant, so its output follows a desired control signal, called the reference, which may be a fixed or changing value. To do this a controller is designed, which monitors the output and compares it with the reference. The difference between actual and desired output, called the error signal, is applied as feedback to the input of the system, to bring the actual output closer to the reference. Some topics studied in control theory are stability (whether the output will converge to the reference value or oscillate about it), controllability and observability.


In control theory observability is a measure for how well internal states of a system can be inferred by knowledge of its external outputs. The observability and controllability of a system are mathematical duals.

First Occurrence Syndrome

The failure to take seriously a warning about a possibility with which they had no prior experience.

Game Theory

Game theory

A kingmaker scenario in a game of three or more players, is an endgame situation where a player who is unable to win has the capacity to determine which player among others will. Said player is referred to as the kingmaker or spoiler. No longer playing for themselves, they may make game decisions to favor a player who played more favorably (to them) earlier in the game. Except in games where interpersonal politics, by design, play a decisive role, this is undesirable.

Seven Deadly Dilemmas

First heard about it at PaX 2017 during a talk in Game Theory. From Rock Paper Scissors: Game Theory in Everyday Life. Found on Jim Shamlin’s reading notes.

  1. The Prisoner’s Dilemma - Two people must trust one another to make a choice that achieves the best outcome for each
  2. The Tragedy of The Commons - Members of a community must make conservative use of a shared resource to avoid destroying it
  3. The Free Rider - A situation in which a third-party benefits from a resource without contributing to it
  4. Playing Chicken - One party takes a position that requires the other to cede, and both suffer if neither does.
  5. The Volunteer’s Dilemma - Members of a group recognize the need for something to be done, and all will suffer if no-one volunteers to do it
  6. Battle of the Sexes - Two individuals want to cooperate, but have different preferences for how to proceed
  7. Stag Hunt - Working cooperatively has a chance of success, but an individual who breaks ranks (foiling the cartel) has a better chance of getting a lesser reward

Observer Effect

The observer effect is the potential impact of the act of observing a process output while the process is running. For example: if a process uses a log file to record its progress, the process could slow. Furthermore, the act of viewing the file while the process is running could cause an I/O error in the process, which could, in turn, cause it to stop.

Another example would be observing the performance of a CPU by running both the observed and observing programs on the same CPU, which will lead to inaccurate results because the observer program itself affects the CPU performance (modern, heavily cached and pipelined CPUs are particularly affected by this kind of observation).

Observing (or rather, debugging) a running program by modifying its source code (such as adding extra output or generating log files) or by running it in a debugger may sometimes cause certain bugs to diminish or change their behavior, creating extra difficulty for the person trying to isolate the bug (see Heisenbug).

The Observer Effect could also refer to other topics.

Ringelmann Effect

The Ringelmann effect is the tendency for individual members of a group to become increasingly less productive as the size of their group increases. This effect, discovered by French agricultural engineer Maximilien Ringelmann (1861–1931), illustrates the inverse relationship that exists between the size of a group and the magnitude of group members’ individual contribution to the completion of a task. While studying the relationship between process loss (i.e., reductions in performance effectiveness or efficiency) and group productivity, Ringelmann (1913) found that having group members work together on a task (e.g., pulling a rope) actually results in significantly less effort than when individual members are acting alone. Furthermore, Ringelmann discovered that as more and more people are added to a group, the group often becomes increasingly inefficient, ultimately violating the notion that group effort and team participation reliably leads to increased effort on behalf of the members.


According to Ringelmann (1913), groups fail to reach their full potential because various interpersonal processes detract from the group’s overall proficiency.[2] Namely, two distinct processes have been identified as potential sources for the reduced productivity of groups: loss of motivation, and coordination problems.

Serial Position Effect

Serial position effect is the tendency of a person to recall the first and last items in a series best, and the middle items worst. The term was coined by Hermann Ebbinghaus through studies he performed on himself, and refers to the finding that recall accuracy varies as a function of an item’s position within a study list. When asked to recall a list of items in any order (free recall), people tend to begin recall with the end of the list, recalling those items best (the recency effect). Among earlier list items, the first few items are recalled more frequently than the middle items (the primacy effect).

Theory of Constraints

  1. What is the value of this new technology?
  2. What limitation does this technology diminish?
  3. What were the policies and rules that governed before trying to adopt this technology?
  4. What must the new policies be when this new technology is used?


Von Restorff Effect

The von Restorff effect, also known as the “isolation effect”, predicts that when multiple homogenous stimuli are presented, the stimulus that differs from the rest is more likely to be remembered.