History[ edit ] The critical period hypothesis was first proposed by Montreal neurologist Wilder Penfield and co-author Lamar Roberts in their book Speech and Brain Mechanisms,  and was popularized by Eric Lenneberg in with Biological Foundations of Language. First-language acquisition relies on neuroplasticity. If language acquisition does not occur by puberty, some aspects of language can be learned but full mastery cannot be achieved. Strictly speaking, the experimentally verified critical period relates to a time span during which damage to the development of the visual system can occur, for example if animals are deprived of the necessary binocular input for developing stereopsis.
Top of Page Describe the organism s used in the study. This includes giving the 1 source supplier or where and how the orgranisms were collected2 typical size weight, length, etc3 how they were handled, fed, and housed before the experiment, 4 how they were handled, fed, and housed during the experiment.
In genetics studies include the strains or genetic stocks used. For some studies, age may be an important factor. For example, did you use mouse pups or adults? Seedlings or mature plants? Describe the site where your field study was conducted. The description must include both physical and biological characteristics of the site pertinant to the study aims.
Include the date s of the study e. Location data must be as precise as possible: When possible, give the actual latitude and longitude position of the site: It is often a good idea to include a map labeled as a Figure showing the study location in relation to some larger more recognizable geographic area.
Someone else should be able to go to the exact location of your study site if they want to repeat or check your work, or just visit your study area.
For laboratory studies you need not report the date and location of the study UNLESS it is necessary information for someone to have who might wish to repeat your work or use the same facility.
Most often it is not. If you have performed experiments at a particular location or lab because it is the only place to do it, or one of a few, then you should note that in your methods and identify the lab or facility.
Top of Page Describe your experimental design clearly. Be sure to include the hypotheses you tested, controls, treatments, variables measured, how many replicates you had, what you actually measured, what form the data take, etc. Always identify treatments by the variable or treatment name, NOT by an ambiguous, generic name or number e.
When your paper includes more than one experiment, use subheadings to help organize your presentation by experiment. A general experimental design worksheet is available to help plan your experiments in the core courses. Describe the procedures for your study in sufficient detail that other scientists could repeat your work to verify your findings.
Foremost in your description should be the "quantitative" aspects of your study - the masses, volumes, incubation times, concentrations, etc. When using standard lab or field methods and instrumentation, it is not always necessary to explain the procedures e.
You may want to identify certain types of equipment by vendor name and brand or category e. It is appropriate to report, parenthetically, the source vendor and catalog number for reagents used, e.
Always make sure to describe any modifications you have made of a standard or published method. Very frequently the experimental design and data collection procedures for an experiment cannot be separated and must be integrated together.
If you find yourself repeating lots of information about the experimental design when describing the data collection procedure slikely you can combine them and be more concise. Of course you did, because that is what all good scientists do, and it is a given that you recorded your measurements and observations.
Describe how the data were summarized and analyzed. Here you will indicate what types of descriptive statistics were used and which analyses usually hypothesis tests were employed to answer each of the questions or hypotheses tested and determine statistical siginifcance.
The information should include: For example, "A Paired t-test was used to compare mean flight duration before and after applying stablizers to the glider's wings.
Here is some additional advice on particular problems common to new scientific writers. The Methods section is prone to being wordy or overly detailed. Avoid repeatedly using a single sentence to relate a single action; this results in very lengthy, wordy passages. A related sequence of actions can be combined into one sentence to improve clarity and readability: This is a very long and wordy description of a common, simple procedure.
It is characterized by single actions per sentence and lots of unnecessary details. The lid was then raised slightly. An inoculating loop was used to transfer culture to the agar surface.
The turntable was rotated 90 degrees by hand.The simplistic definition of the null is as the opposite of the alternative hypothesis, H 1, although the principle is a little more complex than that..
The null hypothesis (H 0) is a hypothesis which the researcher tries to disprove, reject or nullify.. The 'null' often refers to the common view of something, while the alternative hypothesis is what the researcher really thinks is the cause.
How to Write an Abstract. In this Article: Article Summary Getting Your Abstract Started Writing Your Abstract Formatting Your Abstract Community Q&A If you need to write an abstract for an academic or scientific paper, don't panic! Your abstract is simply a short, stand-alone summary of the work or paper that others can use as an overview.
An abstract describes what you do in your essay. As a work of science, "Set Theory and the Continuum Hypothesis" stands on a par with Darwin's "On the Origin of Species".
First, like Darwin's book, Cohen's work is a profound contribution to its field; second it is also accessible to any educated and interested reader, although with some effort. Bought a 5 page english paper.
The writer followed the instructions on what to write for each paragraph. But totally ignored the " don't summarize the story" instruction, and there were many faulty sentences. Every part of the story is important, but nothing is as crucial to captivating the reader as the opening sentence.
Yet many writers overlook the role of the first sentence, starting their novels (short stories, articles) with a cliché, a long boring sentence or even something artificially .
The scientific method is a systematic way of learning about the world around us and answering questions. The key difference between the scientific method and other ways of acquiring knowledge are forming a hypothesis and then testing it with an experiment.