What is Comparison: Definition and 388 Discussions

Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are similar to the other, which are different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field:

To compare is to bring two or more things together (physically or in contemplation) and to examine them systematically, identifying similarities and differences among them. Comparison has a different meaning within each framework of study. Any exploration of the similarities or differences of two or more units is a comparison. In the most limited sense, it consists of comparing two units isolated from each other.
To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and in the arts.

View More On Wikipedia.org
Recent contents Top users
  1. A

    Comparison of two Thermal Physics Books

    Hello everyone! I am taking my Physics Ph. D. Qualifier on Friday and Saturday. During Saturday's exam we will be tested on E&M and Thermodynamics/Statistical Mechanics. We get to take 2 books to each exam, so I basically can take 1 Thermo Book with me (I'm also taking Griffiths on Saturday)...
  2. N

    Is the series sum(1/n!,n,1,inf) convergent?

    sum(1/n!,n,1,inf) the only thing i can think of is 1/n^2>=1/n! , 1/n^2 being a convergent p series since p >1 thus /n! is convergent
  3. N

    Is the Basic Series Comparison Test Applicable for Sum(n^(1/2)/(n^2+1),n,1,inf)?

    14. sum(n^(1/2)/(n^2+1),n,1,inf) b=n^(1/2)/(n^2+2)<=n^(1/2)/(n^2+1)=a b is conv since lim as n-> inf b = 0 since n^(1/2)<n^2+2 for x>=1 thus a is conv i have a feeling this is a shakey way to do this if its even correct somone pleae clarify the solution to this problem
  4. I

    Calculus II - Series Comparison Test Problems

    Homework Statement I have two relatively similar problems: 1.) Sigma n=1 to infinity ((ln n)^3 / n^2) 2.) Sigma n=1 to infinity (1 / sqrt(n) * (ln n)^4) I'm to prove their convergence or divergence using either the direct comparison test or the limit comparison test. I understand...
  5. Andre

    Capturing Nature's Small Wonders: Comparison of Camera Configurations

    It's a great joy to capture small creatures big on the screen without them even noticing it. There are several ways to do that. I used to utilize my old Panasonic FZ-18 bridge camera with a close up lens. Preferably #2 or 2 dioptries or 50 cm focus distance, with a moderate zoom 8-12x you get...
  6. L

    Can the LCT be Used Without Showing the Comparison Test Will Not Work?

    Homework Statement I was just wondering that when applying a comparison test or a limit comparison test, do i have to show that a comparison test does not work in order to use a LCT? Also, if i directly use LCT, will i get the same answer as in the regular comparison test? Thanks...
  7. M

    Aerofoil analysis, CFD and Experimental comparison

    Homework Statement Computational Fluid Dynamics anyone? :D I know someone out there is a genius? I'm trying to understand some of the differences between Experimental results and a Fluent (CFD) analysis of a NACA 0012 aerofoil. There are 3 Cp/x graphs of my results (plotted with negative down...
  8. G

    Comparing Stability of Allylic Carbanions

    Homework Statement Look at the diagram accompanying the question. Which has least C-H bond energy? The Attempt at a Solution On cleavage of a C-H bond, a carbanion is formed as carbon is more electronegative than hydrogen. So cleavage of (b) results in a carbanion stabilized by resonance
  9. W

    Comparison Test: How & Why for Next Step?

    http://img205.imageshack.us/img205/5117/summation.jpg I think next step is: http://img205.imageshack.us/img205/7044/summation2.jpg but the questions are: how & why? why is that the next step? how do I solve such problems?\how do I choose the second part?
  10. J

    Looking for comparison of superconductors

    Hi All I'm looking for a table of Tcs and normal state resistivities for a selection of 'typical' superconductors. I'm sure such a thing must exist in literature, but I'm having trouble locating it. Specifically, I've just finished a dissertation project developing a measurement technique...
  11. S

    The Properties of U235 and U238: A Comparison

    hi Is there any document about the difference between U235 and U238 properties?
  12. Z

    Resistance Comparison P & S

    Homework Statement Two resistors of resistances R1 and R2, with R2 > R1, are connected to a voltage source with voltage V0. When the resistors are connected in series, the current is Is. When the resistors are connected in parallel,the current Ip from the source is equal to 10 Is. Let r be...
  13. M

    DeBroglie Wavelength Comparison

    Homework Statement Compare the deBroglie wavelength for an electron in the n=6 orbit of He+ compared to the n=2 orbit. Is the deBroglie wavelength the same, smaller, or larger? Derive this. Homework Equations Quantization of Paths of Electrons: 2 pi r = n (lambda) Bohr Radius: rn=n2 aB The...
  14. S

    I need electrical comparison help, anybody?

    I want to purchase a dental magneostrictive ultrasonic scaler. I need help with comparisons on technical specifications. Can anyone help me determine what is the best unit as far as output goes, if I give you the specifications? (Obviously I do not know electrical stuff - Just teeth)
  15. J

    Finding Max & Min of f & g: A Comparison

    Homework Statement (a) Let f,g: [a,b] \rightarrow \Re. Define: f \vee g(x) = max(f(x),g(x)), x\in [a,b] f \wedge g(x) = min(f(x),g(x)), x\in [a,b] (b) Let f_{+} = f\vee0, f_{-} = -(f\wedge0) Show that: f = f_{+} - f_{-} abs value of f = f_{+} + f_{-}...
  16. P

    Convergence Tests the Comparison Test

    hey guys I'm kind of stuck on this idea of the comparison test. i understand the process and how it is done but i don't seem to understand how to find the second series(typically called bn) to compare with the original. get what i mean? thanks! =)
  17. A

    Dimensional Analysis - Comparison of exponents

    I have been reading a paper which introduced classical mechanics concerning only one dimension. Before we get into anything about displacement and velocity, I read about dimensional analysis. There is a section of the paper which isn't very well explained and I hope someone can explain it to...
  18. J

    Comparison of Gravitational, Electric, and Magnetic Fields

    Homework Statement Which two of the three types of fields in the title of this are thread are the most similar? Provide supporting evidence? Homework Equations Gravitational: -Source: point mass -Field intensity proportional to: M/r^2 -Range: long range -Strength: weak -Direction of field...
  19. A

    GM Crops vs Organic Farming: Output Per Acre Comparison

    How do GM crops (both current and potential in the near future) compare with organic in terms of output per acre? How does it compete with such methods as Fukuoka Natural Farming, and other forms of permaculture?
  20. F

    DNA Comparison of Potential Energy, RMS Deviation, Electrostatic Energy

    Homework Statement I am comparing a normal DNA decamer molecule with one in which the two strands are only connected by the two base pairs on one of the ends. It was determined that the potential energies of both DNA molecules are negative, with values for the normal DNA much more negative...
  21. M

    Infinite Series Comparison Tests

    Hello, folks. This happens to be my first post here, and I've come with a question from a problem set in my textbook. Homework Statement Determine whether the following series converges or diverges. Give reasons for your answer. Homework Equations \sum^{\infty}_{n=2}...
  22. C

    Comparison of FEA and closed form solution for fluid velocity in a channel

    I am trying to compare the fluid velocity given by the closed form solution and FEA analysis for fluid flowing through a channel that is 800u long and 100u wide. I am using the equation vmax= (gradP)*(radius)^2/(4*viscosity) I got 8.4cm/s in the former compared to ~10cm/s in the latter...
  23. U

    Schools University math curriculum comparison: US v UK

    Disclaimer: Although my question is targeted toward the UK, I do not wish to exclude comparison with other countries e.g. Germany or Canada. Please, if you have studied maths at universities in another country, your experience is of value and interest. Here in the United States, the usual...
  24. U

    Comparison of Improper Integrals

    Homework Statement For what values of p does the following integral converge or diverge? \int^{\infty}_{2}\frac{dx}{x[ln(x)]^{p}} The Attempt at a Solution I have graphed y=\frac{1}{x[ln(x)]^{p}} for different values of p (negative, zero, positive), and it looks as though in all...
  25. J

    Comparison Between Two Isolated Systems

    If we think of two isolated systems, A and B, existing side by side, the proportion of the energy between those systems should always stay the same. Here is a thought, that I would like some comments on: System A contains a planet, and the advanced civilisation on this planet, have created...
  26. V

    Direct and limit comparison test?

    Does anyone have any knowledge on these? I look at an example of a direct or limit comparison and i see what they are doing, but I have no idea how they got the "comprable" term... for example the sum (n = 1) to infinity n/(n^2 +1) you can use either test, but how do you choose what to...
  27. X

    WORK/LEVERAGE comparison HELP

    I need to compare two ICE engines. I need to know the "work" of one compared to another. Let's say the first engine has a bore of 3'' and a sroke of 3" connecting rod 5.25. If you need cylinder presure,say PCP is 5000psi At 20 degrees ATDC and tapers to 800psi at 90 degrees ATDC. The second...
  28. L

    Comparing Quicksort Approaches: Emp Struct vs Emp* Array

    typedef struct Emp { unsigned char lname[MaxName + 1]; /* + 1 for '\0' */ unsigned char fname[MaxName + 1]; unsigned int id; unsigned char dept; bool married; } Emp; int comp1(const void* item1, const void* item2) { const Emp* emp1 = (const Emp*) item1; //emp1...
  29. D

    Comparison between 2 or more quantities

    Hi everyone, I need your help badly. This may sound simple to everyone but I need to get the concept sorted out. For ratios, we know that it is a comparison between 2 or more quantities with the same units. My question is, can ratio be used to compare between say ingredients in a...
  30. M

    Estimating error using comparison/limit comparison test

    I am confused about the right formula for this. Is it R_{n} \leq T_{n} \leq \int_{n+1}^{\infty} or R_{n} \leq T_{n} \leq\int_{n}^{\infty} ? Say for example, I want to estimate the error in using the sum of the first 10 terms to approximate the sum of the series. The textbook seems to use...
  31. B

    Limit Comparison Test for series

    I have been given the series sum 1/sqrt(3n-2) from n=1 to infinity I am supposed to use the limit comparison test, and the comparison series my book suggests is sum 1/sqrt n from n=1 to infinity, which I know is a divergent p series However, when I take the limit of one divided by the...
  32. F

    Measuring Attraction/Repulsion Changes in Sets: A Statistical Approach?

    Hello everybody! I have a large set of items and, two-by-two, there exists some kind of attraction/repulsion that I have measured. I synthesize this information in a (nxn) matrix. Under different circumstances this attraction/repulsion changes. So, what kind of statistical/mathematical...
  33. F

    Comparison of attraction/repulsion measures

    Hello everybody! I have a large set of items and, two-by-two, there exists some kind of attraction/repulsion that I have measured. Under different circumstances this attraction/repulsion changes. So, what kind of statistical/mathematical procedure can I use to measure whether the changes...
  34. T

    Mastering Comparison Tests for Infinite Series

    Not really a specific question, but I am really struggling with the comparison tests for infinite series. I just finished doing quite a few problems from the section. I went in pretty confident, but after completing the section I was bummed that I only did a less than a handful correctly. My...
  35. I

    Question on 3 phase motor comparison

    I'm not sure where to post this one but i'll start with the mechanical guys first. There are two different motors that share identical ratings but different sizes physically. They are represented as though they perform the same work, share a common HP and KW rating and the mechanical device...
  36. J

    Loop Coil Comparison: Hollow Tubing vs. Solid Wire

    Is the same inductance formula valid for a coil made of hollow tubbing that for a solid wire made , with both having the same width?, and supposing that a high frequency current flows through it whats the skin effect influence on the result
  37. R

    Comparing Series: Convergence or Divergence?

    Homework Statement is the series convergent or divergent. Sum from 2 to ∞ of 1/ [n(ln n)^.5] Homework Equations comparison test? The Attempt at a Solution Is it possible to use the comparison test for this problem. Also, could I compare this with something like: (1/[(ln n)^.5]...
  38. F

    Comparison Theorem: Convergence of Integral from 0-->1

    Homework Statement Use the Comparison Theorem to determine whether the integral below is convergent or divergent: e^-x / sqrt x dx integrated from 0-->1 The Attempt at a Solution I think it is convergent because 1/e^x is convergent. I set the original integral less than or equal to the...
  39. tony873004

    Comparison test for convergence

    Homework Statement \sum\limits_{n = 2}^\infty {\frac{{\sqrt n }}{{n - 1}}} Homework Equations The Attempt at a Solution \begin{array}{l} a_n = \frac{{\sqrt n }}{{n - 1}},\,\,b_n = \frac{{\sqrt n }}{n} = \frac{{n^{1/2} }}{n} = \frac{1}{{n^{1/2} }}\,\,{\rm{is_ a_ p - series_...
  40. S

    Comparison of sound waves in air and underwater

    [SOLVED] Comparison of sound waves in air and underwater Homework Statement In air, the human ear is most sensitive to sound waves of 3300Hz. The auditory canal is part of the human ear. It is a tube of length 0.025m, i.e. 1/4 the wavelength of sound with frequency 3300Hz. When under...
  41. P

    Understanding TOE & QG: A Comparison for Physicists

    Just want to get some terminology right. Is TOE equivalent to QG? If so is QG more frequently used by physicsts as it sounds more professional or simply more logical?
  42. M

    Does xn Converge? A Comparison Test

    Homework Statement Does xn converge (Sum from n=1 to infinity) of xn = 1/(n + SQRTn) Homework Equations Using comparision test The Attempt at a Solution I separted into fractions of 1/SQRTn - 1/(1 + SQRTn) and i know that both of these diverge since the power of n is less than...
  43. 5

    Twin or Single Throttle Body Blade Comparison

    Hi all, I have been looking for an answer to this and I cannot find one. So here is my question... The surface area of 57mm twin round throttle body set-up was 5100 mm^2 and the single 75mm throttle body set-up was 4415 mm^2. Now to the actual question... Does smaller (twin)...
  44. L

    Improper Integrals and the Comparison Theorem

    Use the Comparisom Theorem to determine if f(x) = \int^{\infty}_{42} \frac{42+42^-x}{x}dx is convergent or divergent. I compared it to g(x)=\int^{\infty}_{42} \frac{1}{x}dx \int^{\infty}_{42} \frac{1}{x}dx = Lim_{t->\infty}\int^{t}_{42} \frac{1}{x}dx Take the antiderivative, and the limit...
  45. W

    Comparing Currents: Two Wire Comparison Homework

    Homework Statement The diagram shows two wires; wire 1 and wire 2. The charge carriers in wire 1 (of circular cross section and radius R) have a drift speed down the wire that is not constant across the wire. Instead, the drift speed rises linearly from zero at the circumference (r=R) to at...
  46. V

    Decibel Comparison Formulas for Sound Levels

    Hello everyone, Could anyone please show me the appropriate formulas which I need for the following question? 1. How many times louder or softer than sound level of 40 dB is a sound at a) 68 dB? b) 0.3 dB? Thank you.
  47. B

    How pipes in parralel works in comparison to pipes in series

    can anybody focus something on how pipes in parallel will work in comparison to the same pipes in series.i want to calculate pressure drop across 4 parallel pipes emerging from a tank & entering inside the other tank . pipes of sam dia,& same length. thnks
  48. B

    Asynchronous/Synchronous motors comparison?

    Homework Statement What are the differences between AC synchronous motors and AC asynchronous motors. Also, what are the simple and non technical differences between AC and DC motors. Homework Equations The Attempt at a Solution
  49. R

    Choosing Between the Ordinary & Limit Comparison Test

    Homework Statement First questions is: How to choose between using the ordinary comparison test, or using the limit comparison test? Homework Equations The Attempt at a Solution then, for these two problems below, i decide to use the limit comparison test: SUM n_infinity...
  50. E

    Pool Heater Installation and Comparison Questions

    anyone who has a pool heater? or knows how they are installed? if yes...please let me know what is the power rating of the pool heater and what size the pool is..i need it for comparison issues. (power in BTU/Hr, kW, J/s...) thnx Elie
Back
Top