It was assumed that the sampling procedure was purely random with respect to the personality variables under investigation.

In two-stage cluster sampling, a random sampling technique is applied to the elements from each of the selected clusters.

In stratified sampling, a random sample is drawn from each of the strata, whereas in cluster sampling only the selected clusters are studied.

Because a geographically dispersed population can be expensive to survey, greater economy than simple random sampling can be achieved by treating several respondents within a local area as a cluster.

* Simple random sampling

Genetic drift is the change in the relative frequency in which a gene variant ( allele ) occurs in a population due to random sampling.

The generation of random numbers has many uses ( mostly in statistics, for random sampling, and simulation ).

Early systems emphasized predictable outcomes of an industrial product production line, using simple statistics and random sampling.

Research through random sampling in the South Tucson, Arizona area has established that immigration authorities sometimes target the residents of barrios with the use of possibly discriminatory policing based on racial profiling.

In statistics, statistical inference is the process of drawing conclusions from data subject to random variation, for example, observational errors or sampling variation.

More substantially, the terms statistical inference, statistical induction and inferential statistics are used to describe systems of procedures that can be used to draw conclusions from datasets arising from systems affected by random variation, such as observational errors, random sampling, or random experimentation.

For the most part, statistical inference makes propositions about populations, using data drawn from the population of interest via some form of random sampling.

For example, one may assume that the distribution of population values is truly Normal, with unknown mean and variance, and that datasets are generated by ' simple ' random sampling.

For example, every continuous probability distribution has a median, which may be estimated using the sample median or the Hodges-Lehmann-Sen estimator, which has good properties when the data arise from simple random sampling.

Incorrect assumptions of ' simple ' random sampling can invalidate statistical inference.

A sample that is not random is called a non-random sample or a non-probability sampling.

Then simple random sampling or systematic sampling is applied within each stratum.

A stratified survey could thus claim to be more representative of the population than a survey of simple random sampling or systematic sampling.

In this technique, the total population is divided into these groups ( or clusters ) and a simple random sample of the groups is selected.

A precedent of the technique occurred during a Dadaist rally in the 1920s in which Tristan Tzara offered to create a poem on the spot by pulling words at random from a hat.

The S-boxes of DES were much more resistant to the attack than if they had been chosen at random, strongly suggesting that IBM knew about the technique in the 1970s.

A famous paper by mathematician and magician Persi Diaconis and mathematician Dave Bayer on the number of shuffles needed to randomize a deck concluded that the deck did not start to become random until five good riffle shuffles, and was truly random after seven, in the precise sense of variation distance described in Markov chain mixing time ; of course, you would need more shuffles if your shuffling technique is poor.

A vase glazed and fired using the western raku technique, showing the soot, crackle glazing, and random reduction-oxidation typical of this pottery technique.

In dynamic random access memory ( DRAM ) devices, storage capacitors are also fabricated at this time, typically stacked above the access transistor ( implementing them as trenches etched deep into the silicon surface was a technique developed by the now defunct DRAM manufacturer Qimonda ).

* Signature tagged mutagenesis, a genetic technique to create random mutants

The name of the technique refers to the fact that the testers should be random people who pass by in the hallway.

The technique uses modified retroviruses to transform the cells ; this is a potential problem for human therapy since these viruses integrate their genes at a random location in the host's genome, which can interrupt other genes and potentially causes cancer.

A similar technique was sometimes used to get the first call for prizes in radio " call-in " shows, thus leading to the adoption of random " fifth caller ," " seventeenth caller " etc.

" Demon dialing " is sometimes used as a synonym for war dialing, a related technique which uses automated computer modem dialing, though instead to conduct a random search to locate other modem-connected lines.

In the 1980s researcher H. Mario Geysen developed this technique further, creating arrays of different peptides on separate supports, but not a combinatorial library based on random synthesis.

These lines were created by using a randomization technique where random samples were taken from one of four categories.

* Simulated annealing ( SA ) is a related global optimization technique that traverses the search space by testing random mutations on an individual solution.

A local station generates a pseudo random bit sequence and transmits it to the remote location ( using any modulation technique ).

The technique of using arrows to change control flow is demonstrated in the random number generator program below.

Cut-up technique is a literary form or method in which a text is cut up at random and rearranged to create a new text.

One method to create a strong passphrase is to use dice to select words at random from a long list, a technique often referred to as diceware.

Bias field estimation is a real preprocessing technique using mathematical models of the noise from distortion, such as Markov random fields and expectation maximization algorithms, to correct for distortion.

* Successive over-relaxation: A Monte Carlo version of this technique can be seen as a variation on Gibbs sampling ; it sometimes avoids random walks.

Creating tables stored in random access memory is a common code optimization technique in computer programming, where the use of such tables speeds up calculations in those cases where a table lookup is faster than the corresponding calculations ( particularly if the computer in question doesn't have a hardware implementation of the calculations ).

If a work is divided into several large segments, a last-minute drawing of random numbers may determine the order of the segments for any particular performance.

Here the number of trials is a random variable, not a fixed number.

Thus we do not score the number of bull's-eyes, and the random variable is not the number of successes.

The several trials of a binomial experiment produce a new random variable X, the total number of successes, which is just the sum of the random variables associated with the single trials.

The number of successes on each shot is a value of a random variable that has values 0 or 1, and there are 5 such random variables here.

When an occurrence Af is isolated during text reading, a random memory address Af, the address of a cell in the X-region, is computed from the form of Af.

A random address Af that lies within the X-region of memory mentioned earlier is computed from the i-th dictionary form.

The aesthetic appeal of pure paint laid on at random may exist, but it is a very impoverished appeal.

This process is especially difficult since gyro drifting is typically random.

There is no justification for systematizing the random statements of Irenaeus about the image of God beyond this, nor for reading into his imprecise usage the later theological distinction between the image of God ( humanity ) and the similitude of God ( immortality ).

the result of the effect and is partially random error.

The transition from one state to the next is not necessarily deterministic ; some algorithms, known as randomized algorithms, incorporate random input.

They reasoned that if all three families had a common ancestor, we should expect losses to happen at random, not only at the geographical margins of the family, and that the observed pattern is consistent with borrowing.

As this direction is random, the beam could be expected to spread into a line.

The primary disadvantage of analog signaling is that any system has noise – i. e., random unwanted variation.

As the signal is copied and re-copied, or transmitted over long distances, these apparently random variations become dominant.

If no address is provided, one is picked at random from the " base subnet ", 0.

The large and diverse population of antibodies is generated by random combinations of a set of gene segments that encode different antigen binding sites ( or paratopes ), followed by random mutations in this area of the antibody gene, which create further diversity.

Asked to identify the missing Cookies, Hapgood begins questioning random people and sorting them into two groups, group A, and group one, but refuses to divulge which group is which.