Internal vs external validity

When testing cause-and-effect relationships, validity can be split up into two types: internal and external validity.

Internal validity refers to the degree of confidence that the causal relationship being tested is trustworthy and not influenced by other factors or variables.

External validity refers to the extent to which results from a study can be applied (generalized) to other situations, groups or events.

The validity of a study is largely determined by the research design: what, how, where and when the study was executed. To ensure the validity of the tools or tests you use, you also have to consider measurement validity.

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Dissertation binding and printing

Your dissertation is finally finished, you got it proofread and checked for plagiarism. The final step is printing your dissertation, which means choosing between:

  • Types of binding
  • Colour vs. black & white
  • Single vs. double sided
  • Paper type and thickness

You also need to decide which printing and binding service to use. This independent article explains all options and helps you make the right decisions.

Overview of printing services

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How to transcribe an interview

Transcribing is converting speech to text word for word. Transcribing is a common practice when conducting interviews because it enables you to perform analysis.

How to transcribe an interview in five steps:

  1. Choose between verbatim, intelligent verbatim, or edited transcription
  2. Transcribe the audio (use transcription software)
  3. Add speaker designation and time stamps
  4. Clarify the transcript where needed
  5. Proofread the transcript

Transcription software comparison

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Inductive vs. deductive reasoning

Inductive reasoning aims at developing a theory. It moves from specific observations to broad generalizations. Deductive reasoning aims at testing an existing theory. It moves from broad generalizations to specific observations.

Both approaches are used in various types of research, and it’s not uncommon to combine them in one large study.

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Qualitative vs. quantitative research

There are two approaches to collecting and analyzing data: qualitative research and quantitative research. Each of these types of research has different objectives and methods, and both are important for gaining different kinds of knowledge.

Quantitative research

Quantitative research is expressed in numbers and graphs. It is used to test or confirm theories and assumptions. This type of research can be used to establish generalizable facts about a topic.

Qualitative research

Qualitative research is expressed in words. It is used to understand concepts, thoughts or experiences. This type of research enables you to gather in-depth insights on topics that are not well understood.

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Chicago Style Citation

Chicago Manual of StyleThis quick guide, based on The Chicago Manual of Style (17th edition), explains how to create Chicago style citations. Other well-known citation styles inlcude MLA Citation Style and APA Citation Style.

Chicago Style has two systems for citing sources:

  1. Notes and Bibliography, which works with footnotes or endnotes, often accompanied by a bibliography. This system is mainly used in humanities subjects.
  2. Author-Date References, which works with parenthetical citations (reporting only the author and publication date). In-text citations are always accompanied by a bibliography. This system is mostly used in sciences and social sciences.

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APA in-text citation

APA in-text citations consist of the author’s last name, publication year and, if applicable, page numbers. Page numbers are required when quoting and encouraged when paraphrasing. Omit page numbers when referring to a source as a whole.

In-text citation can be included in multiple ways:

  • The author claims that “plagiarism is becoming a bigger problem” (Smith, 2014, p. 170).
  • Smith states that plagiarism is an increasingly big problem (2014, p. 170).
  • The study of Smith shows that plagiarism is an increasingly big issue (2014).

You can easily generate your in-text citations (and full reference list) in APA format with Scribbr’s free citation generator.

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Free plagiarism checker comparison

Free plagiarism checkers are popular. Many students, marketers and text writers use them to avoid plagiarism. We conducted research to answer two main questions:

  1. Which plagiarism checkers are really free?
  2. How much plagiarism is detected by each plagiarism checker?
Overview of free plagiarism checkers
Plagiarism checkerPlagiarism detectedReally free?Restrictions
Scribbr44%Not freeBest plagiarism checker 2019
1. Quetext29%Only free trial3 x 500 words
2. EasyBib19%Only free trial3 days (credit card required)
3. PlagScan17%Only free trial2,000 words
4. Plagramme16%Not freeOnly shows percentage
5. Copyleaks7%100% free2,500 words p/m for free
6. Small SEO Tools5%100% freeMax. 1,000 words per check
7. Grammarly1%Not freeOnly shows percentage
8. Search Engine Reports4%100% freeMax. 1,000 words per check
9. PaperRater0%100% free10 checks per month
10. Edubirdie4%100% freeMight not be safe to use


  • Almost all 100% free plagiarism checkers detect very little plagiarism.
  • Plagiarism checkers that offer a free trial perform much better. However, you will probably end up paying for the service.

For comparison purposes, we added the Scribbr Plagiarism Checker, which is the best plagiarism checker as of 2019. It’s not free, but it does detect the most plagiarism of all plagiarism checkers.

Read the reviews

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