Researching Internet Based Populations Advantages and Disadvantages of Online Survey Research, Online Questionnaire Authoring Software Packages, and Web Survey Services Wright 2.Journal of Computer Mediated Communication.Introduction. The past decade has seen a tremendous increase in internet use and computer mediated communication Fox, Rainie, Larsen, Horrigan, Lenhart, Spooner, Carter, 2.Horrigan, 2. 00. 1 Nie Erbring, 2.Nie, Hillygus, Erbring, 2.As an increasing amount of communicative activity takes place through this new medium, there has likewise been a significant increase in primary research on virtual communities, online relationships, and a variety of other aspects of computer mediated communication Flaherty, Pearce, Rubin, 1.Top Picks for Nonprofits.No matter your organizations tech needs, TechSoup has something for you.Save on software from top vendors like Microsoft, Adobe, Intiut.Volume 6, No. 2, Art.May 2005 Participant Observation as a Data Collection Method.Barbara B. Kawulich.Abstract Observation, particularly participant.Matheson, 1. 99. 1 Nonnecke, Preece, Andrews, Voutour, 2.Preece, 1. 99. 9 Preece Ghozati, 2.Walther, 1. 99. 6 Walther Boyd, 2.Wood Smith, 2. Wright, 2.Advantages And Disadvantages Of Sage Software' title='Advantages And Disadvantages Of Sage Software' />Studies of online populations have led to an increase in the use of online surveys, presenting scholars with new challenges in terms of applying traditional survey research methods to the study of online behavior and Internet use Andrews, Nonnecke, Preece, 2.Bachmann Elfrink, 1.Stanton, 1. 99. 8 Witmer, Colman, Katzman, 1.Yun Trumbo, 2. The technology for online survey research is young and evolving.Until recently, creating and conducting an online survey was a time consuming task requiring familiarity with web authoring programs, HTML code, and scripting programs.Today, survey authoring software packages and online survey services make online survey research much easier and faster.Yet many researchers in different disciplines may be unaware of the advantages and disadvantages associated with conducting survey research online.Advantages include access to individuals in distant locations, the ability to reach difficult to contact participants, and the convenience of having automated data collection, which reduces researcher time and effort.Disadvantages of online survey research include uncertainty over the validity of the data and sampling issues, and concerns surrounding the design, implementation, and evaluation of an online survey.This article considers and evaluates the advantages and disadvantages related to conducting online surveys identified in previous research.In addition, it reviews the current state of available web survey software packages and services, various features of these software packages and services, and their advantages and limitations.The purpose of the article is to provide an overview of issues and resources in order to assist researchers in determining if they would benefit from using online surveys, and to guide them in the selection and use of online survey techniques.To facilitate these goals, which are both methodological and applied, the author draws on published research dealing with online survey methods, as well as his experience conducting more than 1.Advantages of Online Survey Research.Researchers in a variety of disciplines may find the Internet a fruitful area for conducting survey research.As the cost of computer hardware and software continues to decrease, and the popularity of the Internet increases, more segments of society are using the Internet for communication and information Fox et al., 2.Nie et al., 2. 00.Thousands of groups and organizations have moved online, many of them aggressively promoting their presence through the use of search engines, email lists, and banner advertisements.These organizations not only offer information to consumers, they also present opportunities for researchers to access a variety of populations who are affiliated with these groups.Online Accounting Software Compare leading online accounting systems to find the right solution for your business.Free demos, price quotes and reviews Issuu is a digital publishing platform that makes it simple to publish magazines, catalogs, newspapers, books, and more online.Easily share your publications and get.Communication researchers may find the Internet an especially rich domain for conducting survey research.Virtual communities have flourished online, and hundreds of thousands of people regularly participate in discussions about almost every conceivable issue and interest Horrigan, 2.Wellman, 1. 99. 7 Wellman Haythornthwaite, 2.Areas as diverse as interpersonal Parks Floyd, 1.Tidwell Walther, 2.Wright, 2. 00. 4, group Hollingshead, Mc.Grath, OConnor, 1. Location Area Update Procedure 3Gpp Codec here. Hobman, Bordia, Irmer, Chang, 2.Ahuja Carley, 1. Rice Katz, 2.Wright, 2. 00. 0a, and mass communication Flaherty et al.Flanagin Metzger, 2.Access to Unique Populations.One advantage of online survey research is that it takes advantage of the ability of the Internet to provide access to groups and individuals who would be difficult, if not impossible, to reach through other channels Garton, Haythornthwaite, Wellman, 1.Wellman, 1. 99. 7.In many cases, communities and groups exist only in cyberspace.For example, it would be difficult to find a large, concentrated group of people conducting face to face discussions of topics such as cyber stalking, online stock trading, and the pros and cons of virtual dating.While people certainly discuss such issues among friends, family members, and co workers, few meet face to face in large groups to discuss them.UoP/file/fa9fbb2f-06fb-4fef-9ce1-c5e06b26a831/1/Questionnaires_IMSLRN.zip/images/pic003.jpg' alt='Advantages And Disadvantages Of Sage Software' title='Advantages And Disadvantages Of Sage Software' />One advantage of virtual communities as sites for research is that they offer a mechanism through which a researcher can gain access to people who share specific interests, attitudes, beliefs, and values regarding an issue, problem, or activity.For example, researchers can find a concentrated number of older individuals who use computers on the Internet based community Senior.Net Furlong, 1. 98.Wright, 2. 00. 0a, 2.In contrast, with traditional survey research methods it may be more difficult to reach a large number of demographically similar older people who are interested in computers.Another example is the case of individuals with diseases or conditions, such as HIV, eating disorders, and physical disabilities.Individuals with these conditions and diseases are often difficult to reach because they are stigmatized offline.Health communication researchers have been able to go online to study these populations, including examining how features of the computer medium help people cope with the social stigma of their condition Braithwaite, Waldron, Finn, 1.Wright, 2. 00. 0b.More generally, the Internet enables communication among people who may be hesitant to meet face to face.For example, individuals with unpopular political views may hesitate to express themselves openly, and groups of individuals such as Arab Americans may feel uncomfortable talking about anti Arab sentiment in public places Muhtaseb, 2.These individuals and groups often can be reached on the Internet in larger numbers than would be possible using face to face research methods.Time. A second advantage is that Internet based survey research may save time for researchers.As already noted, online surveys allow a researcher to reach thousands of people with common characteristics in a short amount of time, despite possibly being separated by great geographic distances Bachmann Elfrink, 1.Garton et al., 2.Taylor, 2. 00. 0 Yun Trumbo, 2.A researcher interested in surveying hard to reach populations can quickly gain access to large numbers of such individuals by posting invitations to participate to newsgroups, chat rooms, and message board communities.In the face to face research environment, it would take considerably longer if it were possible at all to find an equivalent number of people with specific attributes, interests, and attitudes in one location.Online surveys may also save time by allowing researchers to collect data while they work on other tasks Llieva, Baron, Healey, 2.Once an invitation to participate in a survey is posted to the website of a community of interest, emailed to people through a listserv service, or distributed through an online survey research service, researchers may collect data while working on other projects Andrews et al., 2.Responses to online surveys can be transmitted to the researcher immediately via email, or posted to an HTML document or database file.This allows researchers to conduct preliminary analyses on collected data while waiting for the desired number of responses to accumulate Llieva et al., 2.First generation online survey researchers often used email based surveys, which involved creating online survey forms using word processing software, and later used products such as Macromedias Dreamweaver.Mersenne Twister Wikipedia.The Mersenne Twister is a pseudorandom number generator PRNG.It is by far the most widely used general purpose PRNG.Its name derives from the fact that its period length is chosen to be a Mersenne prime.The Mersenne Twister was developed in 1.Makoto Matsumoto ja and Takuji Nishimura.It was designed specifically to rectify most of the flaws found in older PRNGs.It was the first PRNG to provide fast generation of high quality pseudorandom integers.The most commonly used version of the Mersenne Twister algorithm is based on the Mersenne prime 2.The standard implementation of that, MT1.There is another implementation that uses a 6.MT1. 99. 37 6. 4 it generates a different sequence.Adoption in software systemseditThe Mersenne Twister is the default PRNG for the following software systems Microsoft Visual C,3Microsoft Excel,4GAUSS,5GLib,6GNU Multiple Precision Arithmetic Library,7GNU Octave,8GNU Scientific Library,9gretl,1.IDL,1. 1Julia,1. CMU Common Lisp,1.Embeddable Common Lisp,1.Steel Bank Common Lisp,1.Maple,1. 6MATLAB,1.Free Pascal,1. 8PHP,1.Python,2. 02. 1R,2.Ruby,2. 3Sage. Math,2.Scilab,2. 5Stata.It is also available in Apache Commons,2.C since C1. 1,2. Mathematica.Add on implementations are provided in many program libraries, including the Boost C Libraries,3.CUDA Library,3. 2 and the NAG Numerical Library.The Mersenne Twister is one of two PRNGs in SPSS the other generator is kept only for compatibility with older programs, and the Mersenne Twister is stated to be more reliable.The Mersenne Twister is similarly one of the PRNGs in SAS the other generators are older and deprecated.AdvantageseditThe commonly used version of Mersenne Twister, MT1.It has a very long period of 2.While a long period is not a guarantee of quality in a random number generator, short periods such as the 2.It is k distributed to 3.It passes numerous tests for statistical randomness, including the Diehard tests.DisadvantageseditThe large state space comes with a performance cost the 2.Ki. B state buffer will place a load on the memory caches.In 2. 01. 1, Saito Matsumoto proposed a version of the Mersenne Twister to address this issue.The tiny version, Tiny.MT, uses just 1. 27 bits of state space.By todays standards, the Mersenne Twister is somewhat slow, 3.SFMT implementation is used see section below.It passes most, but not all, of the stringent Test.U0. 1 randomness tests.Because it is based on simple linear xor operations, it fails tests based on linear complexity after relatively few bits of output, despite its extremely large state.Passing the output through a simple hash function can remedy this weakness.Multiple Mersenne Twister instances that differ only in seed value but not other parameters are not generally appropriate for Monte Carlo simulations that require independent random number generators, though there exists a method for choosing multiple sets of parameter values.It can take a long time to start generating output that passes randomness tests, if the initial state is highly non randomparticularly if the initial state has many zeros.A consequence of this is that two instances of the generator, started with initial states that are almost the same, will usually output nearly the same sequence for many iterations, before eventually diverging.The 2. 00. 2 update to the MT algorithm has improved initialization, so that beginning with such a state is very unlikely.A pseudorandom sequence xi of w bit integers of period P is said to be k distributed to v bit accuracy if the following holds.Let truncvx denote the number formed by the leading v bits of x, and consider P of the kv bit vectors.Pdisplaystyle texttruncvxi,texttruncvxi1,.P. Then each of the 2kv possible combinations of bits occurs the same number of times in a period, except for the all zero combination that occurs once less often.AlternativeseditThe algorithm in its native form is not cryptographically secure.The reason is that observing a sufficient number of iterations 6.MT1. 99. 37, since this is the size of the state vector from which future iterations are produced allows one to predict all future iterations.A pair of cryptographic stream ciphers based on output from the Mersenne Twister has been proposed by Matsumoto, Nishimura, and co authors.The authors claim speeds 1.Advanced Encryption Standard in counter mode.An alternative generator, WELL Well Equidistributed Long period Linear, offers quicker recovery, and equal randomness, and nearly equal speed.Marsaglias xorshift generators and variants are the fastest in this class.Algorithmic detailedit.Visualisation of generation of pseudo random 3.Mersenne Twister.The Extract number section shows an example where integer 0 has already been output and the index is at integer 1.Generate numbers is run when all integers have been output.For a w bit word length, the Mersenne Twister generates integers in the range 0, 2w1.The Mersenne Twister algorithm is based on a matrix linear recurrence over a finite binaryfield.F2. The algorithm is a twisted generalised feedback shift register4.GFSR, or TGFSR of rational normal form TGFSRR, with state bit reflection and tempering.The basic idea is to define a series xidisplaystyle xi through a simple recurrence relation, and then output numbers of the form xi.Tdisplaystyle xiT, where Tdisplaystyle T is an invertible F2 matrix called a tempering matrix.The general algorithm is characterized by the following quantities some of these explanations make sense only after reading the rest of the algorithm w word size in number of bitsn degree of recurrencem middle word, an offset used in the recurrence relation defining the series x, 1 m lt nr separation point of one word, or the number of bits of the lower bitmask, 0 r w 1a coefficients of the rational normal form twist matrixb, c TGFSRR tempering bitmaskss, t TGFSRR tempering bit shiftsu, d, l additional Mersenne Twister tempering bit shiftsmaskswith the restriction that 2nw r 1 is a Mersenne prime.This choice simplifies the primitivity test and k distribution test that are needed in the parameter search.The series x is defined as a series of w bit quantities with the recurrence relation xkn xkmxkuxk1lAk0,1,displaystyle xkn xkmoplus leftxkumid mid xk1lArightqquad qquad k0,1,ldots where displaystyle mid mid denotes concatenation of bit vectors with upper bits on the left, displaystyle oplus the bitwise exclusive or XOR, xkudisplaystyle xku means the upper wrdisplaystyle w r bits of xkdisplaystyle xk, and xk1ldisplaystyle xk1l means the lower rdisplaystyle r bits of xk1displaystyle xk1.The twist transformation A is defined in rational normal form as A0.Iw1aw1aw2,a. Abeginpmatrix0 Iw 1aw 1 aw 2,ldots ,a0endpmatrixwith In 1 as the n 1 n 1 identity matrix.The rational normal form has the benefit that multiplication by A can be efficiently expressed as remember that here matrix multiplication is being done in F2, and therefore bitwise XOR takes the place of additionx.Ax1x. 00x1ax. Abegincasesboldsymbol xgg 1 x00boldsymbol xgg 1oplus boldsymbol a x01endcaseswhere x.As like TGFSRR, the Mersenne Twister is cascaded with a tempering transform to compensate for the reduced dimensionality of equidistribution because of the choice of A being in the rational normal form.Note that this is equivalent to using the matrix A where.A T1. AT for T an invertible matrix, and therefore the analysis of characteristic polynomial mentioned below still holds.As with A, we choose a tempering transform to be easily computable, and so do not actually construct T itself.
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