Index

An index is an indirect shortcut derived from and pointing into a greater volume of values, data, information or knowledge. Index may refer to:

Business

Publishing

Index (statistics)

In statistics and research design, an index is a composite statistic – a measure of changes in a representative group of individual data points, or in other words, a compound measure that aggregates multiple indicators. Indexes summarize and rank specific observations.

Much data in the field of social sciences is represented in various indices such as Gender Gap Index, Human Development Index or the Dow Jones Industrial Average.

Item in indexes are usually weighted equally, unless there are some reasons against it (for example, if two items reflect essentially the same aspect of a variable, they could have a weight of 0.5 each).

Constructing the items involves four steps. First, items should be selected based on their face validity, unidimensionality, the degree of specificity in which a dimension is to be measured, and their amount of variance. Items should be empirically related to one another, which leads to the second step of examining their multivariate relationships. Third, indexes scores are designed, which involves determining their score ranges and weights for the items. Finally, indexes should be validateds, which involves testing whether they can predict indicators related to the measured variable not used in their construction.

Index of a subgroup

In mathematics, specifically group theory, the index of a subgroup H in a group G is the "relative size" of H in G: equivalently, the number of "copies" (cosets) of H that fill up G. For example, if H has index 2 in G, then intuitively "half" of the elements of G lie in H. The index of H in G is usually denoted |G : H| or [G : H] or (G:H).

Formally, the index of H in G is defined as the number of cosets of H in G. (The number of left cosets of H in G is always equal to the number of right cosets.) For example, let Z be the group of integers under addition, and let 2Z be the subgroup of Z consisting of the even integers. Then 2Z has two cosets in Z (namely the even integers and the odd integers), so the index of 2Z in Z is two. To generalize,

for any positive integer n.

If N is a normal subgroup of G, then the index of N in G is also equal to the order of the quotient group G / N, since this is defined in terms of a group structure on the set of cosets of N in G.

If G is infinite, the index of a subgroup H will in general be a non-zero cardinal number. It may be finite - that is, a positive integer - as the example above shows.

Bliss

Bliss may refer to:

People

Bliss (image)

Bliss is the name of the default computer wallpaper of Microsoft's Windows XP operating system. It is an image of a rolling green hill and a blue sky with cumulus and cirrus clouds. The landscape depicted is in the Los Carneros American Viticultural Area of Sonoma County, California, United States.

Overview

Former National Geographic photographer Charles O'Rear, a resident of the nearby Napa Valley, took the photo on film with a medium-format camera while on his way to visit his girlfriend in 1996. While it was widely believed later that the image was digitally manipulated or even created with software such as Adobe Photoshop, O'Rear says it never was. He sold it to Corbis for use as a stock photo. Several years later, Microsoft engineers chose a digitized version of the image and licensed it from O'Rear.

Over the next decade it has been claimed to be the most viewed photograph in the world during that time. Since it was taken, the landscape in it has changed, with grapevines planted on the hill and field in the foreground, making O'Rear's image impossible to duplicate for the time being. That has not stopped other photographers from trying, and some of their attempts have been included in art exhibits.

Bliss (12 Rods album)

Bliss is a 1993 album by 12 Rods.

Track listing