Civil Rights
Movements, leaders, victories and the continuing fight for equality.
q2K BHP
Black History Portal
THE BHP WIRE —
HIDDEN TRUTHS
What's New!
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
Katherine Johnson’s mathematical calculations helped guide some of America’s most important early space missions while she confronted the racial and gender barriers faced by Black women in twentieth-century America.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
Value of information (VOI or VoI) is the amount a decision maker would be willing to pay for information prior to making a decision.
VoI is sometimes distinguished into value of perfect information, also called value of clairvoyance (VoC), and value of imperfect information. They are closely related to the widely known expected value of perfect information (EVPI) and expected value of sample information (EVSI). Note that VoI is not necessarily equal to "value of decision situation with perfect information" - "value of current decision situation" as commonly understood.
A simple example best illustrates the concept: Consider the decision situation with one decision, for example deciding on a 'Vacation Activity'; and one uncertainty, for example what will the 'Weather Condition' be? But we will only know the 'Weather Condition' after we have decided and begun the 'Vacation Activity'.
The above definition illustrates that the value of imperfect information of any uncertainty can always be framed as the value of perfect information, i.e., VoC, of another uncertainty, hence only the term VoC will be used onwards.
Consider a general decision situation[1] having n decisions (d1, d2, d3, ..., dn) and m uncertainties (u1, u2, u3, ..., um). Rationality assumption in standard individual decision-making philosophy states that what is made or known are not forgotten, i.e., the decision-maker has perfect recall. This assumption translates into the existence of a linear ordering of these decisions and uncertainties such that;
Consider cases where the decision-maker is enabled to know the outcome of some additional uncertainties earlier in his/her decision situation, i.e., some ui are moved to appear earlier in the ordering. In such case, VoC is quantified as the highest price which the decision-maker is willing to pay for all those moves.
The standard then is further generalized in team decision analysis framework where there is typically incomplete sharing of information among team members under the same decision situation. In such case, what is made or known might not be known in later decisions belonging to different team members, i.e., there might not exist linear ordering of decisions and uncertainties satisfying perfect recall assumption. VoC thus captures the value of being able to know "not only additional uncertainties but also additional decisions already made by other team members" before making some other decisions in the team decision situation.[2]
There are four characteristics of VoI that always hold for any decision situation:
VoC is derived strictly following its definition as the monetary amount that is big enough to just offset the additional benefit of getting more information. In other words; VoC is calculated iteratively until
A special case is when the decision-maker is risk neutral where VoC can be simply computed as
This special case is how expected value of perfect information and expected value of sample information are calculated where risk neutrality is implicitly assumed. For cases where the decision-maker is risk averse or risk seeking, this simple calculation does not necessarily yield the correct result, and iterative calculation is the only way to ensure correctness.
Decision trees and influence diagrams are most commonly used in representing and solving decision situations as well as associated VoC calculation. The influence diagram, in particular, is structured to accommodate team decision situations where incomplete sharing of information among team members can be represented and solved very efficiently. While decision trees are not designed to accommodate team decision situations, they can do so by augmenting them with information sets widely used in game trees.
VoC is often illustrated using the example of paying for a consultant in a business transaction, who may either be perfect (expected value of perfect information) or imperfect (expected value of imperfect information).[3]
In a typical consultant situation, the consultant would be paid up to cost c for their information, based on the expected cost E without the consultant and the revised cost F with the consultant's information. In a perfect information scenario, E can be defined as the sum product of the probability of a good outcome g times its cost k, plus the probability of a bad outcome (1-g) times its cost k'>k:
E = gk + (1-g)k',
which is revised to reflect expected cost F of perfect information including consulting cost c. The perfect information case assumes the bad outcome does not occur due to the perfect information consultant.
F = g(k+c)
We then solve for values of c for which F<E to determine when to pay the consultant.
In the case of a recursive decision tree, we often have an additional cost m that results from correcting the error, and the process restarts such that the expected cost will appear on both the left and right sides of our equations.[4] This is typical of hiring-rehiring decisions or value chain decisions for which assembly line components must be replaced if erroneously ordered or installed:
E = gk + (1-g)(k'+m+E)
F = g(k+c)
If the consultant is imperfect with frequency f, then the consultant cost is solved with the probability of error included:
F = g(k+c)(1-f) + g(k+c+F)f + (1-g)(1-f)(k+c+F) + (1-g)f(k'+c+m+F)
VoI is also used to do an inspection and maintenance planning of the structures. analyze to what extent the value associated with the information collected during the service life of engineered structures, for example, inspections, in the context of integrity management, is affected by not only measurement random errors but also biases (systematic errors), taking the dependency between the collections into account[5]
{{citation}}: ISBN / Date incompatibility (help)
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
Value of information (VOI or VoI) is the amount a decision maker would be willing to pay for information prior to making a decision.
In decision theory, the expected value of perfect information (EVPI) is the price that one would be willing to pay in order to gain access to perfect information. A common discipline that uses the EVPI concept is health economics. In that context and when looking at a decision of whether to adopt a new treatment technology, there is always some degree of uncertainty surrounding the decision, because there is always a chance that the decision turns out to be wrong. The expected value of perfect information analysis tries to measure the expected cost of that uncertainty, which “can be interpreted as the expected value of perfect information (EVPI), since perfect information can eliminate the possibility of making the wrong decision” at least from a theoretical perspective.
In decision theory, the expected value of sample information (EVSI) is the expected increase in utility that a decision-maker could obtain from gaining access to a sample of additional observations before making a decision. The additional information obtained from the sample may allow them to make a more informed, and thus better, decision, thus resulting in an increase in expected utility. EVSI attempts to estimate what this improvement would be before seeing actual sample data; hence, EVSI is a form of what is known as preposterior analysis. The use of EVSI in decision theory was popularized by Robert Schlaifer and Howard Raiffa in the 1960s.
The value of structural health information is the expected utility gain of a built environment system by information provided by structural health monitoring (SHM). The quantification of the value of structural health information is based on decision analysis adapted to built environment engineering. The value of structural health information can be significant for the risk and integrity management of built environment systems.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Joe Louis.
