{"id":764,"date":"2023-03-08T17:54:10","date_gmt":"2023-03-08T17:54:10","guid":{"rendered":"https:\/\/content.one.lumenlearning.com\/introstatstest\/chapter\/advanced-experimental-design-learn-it-1\/"},"modified":"2025-10-05T16:09:08","modified_gmt":"2025-10-05T16:09:08","slug":"advanced-experimental-design-learn-it-1","status":"publish","type":"chapter","link":"https:\/\/content.one.lumenlearning.com\/introstatstest\/chapter\/advanced-experimental-design-learn-it-1\/","title":{"raw":"Advanced Experimental Design: Learn It 1","rendered":"Advanced Experimental Design: Learn It 1"},"content":{"raw":"<section class=\"textbox learningGoals\">\r\n<ul>\r\n\t<li>Review an experiment and explain if it has been designed well<\/li>\r\n\t<li>Use randomized block design to create a hypothetical experiment to answer a research question<\/li>\r\n<\/ul>\r\n<\/section>\r\n<h2>Well-Designed Experiments<\/h2>\r\n<p>The primary goal of an\u00a0experiment\u00a0is to provide evidence for a cause-and-effect relationship between two variables.<\/p>\r\n<section class=\"textbox recall\">\r\n<ul>\r\n\t<li><strong>Factor of interest:<\/strong> The explanatory variable (independent variable), which is what we suspect has an effect on the response variable.<\/li>\r\n\t<li><strong>Response factor\/variable:<\/strong> The dependent variable, which we suspect is affected by the factor of interest.<\/li>\r\n<\/ul>\r\n<\/section>\r\n<section class=\"textbox tryIt\">[ohm2_question hide_question_numbers=1]719[\/ohm2_question]<\/section>\r\n<p>In an experiment, the researcher manipulates values of the explanatory variable and measures the resulting changes in the response variable. The different values of the explanatory variable are called\u00a0<strong>treatments<\/strong>.<\/p>\r\n<section class=\"textbox keyTakeaway\">\r\n<div>\r\n<h3>treatments<\/h3>\r\n<strong>Treatments <\/strong>are experimental conditions into which the participants are divided, some into a group receiving the treatment of interest and others into a control group that does not receive the treatment (a placebo). <br \/>\r\n<br \/>\r\nA <strong>placebo<\/strong>\u00a0is a harmless version of the treatment that does not contain any active ingredients (e.g., a sugar pill).\u00a0The placebo will typically look, taste, and smell like the treatment of interest or mimic it so that the two treatments appear identical to the subjects; this way the subjects don\u2019t know which treatment they are receiving.<\/div>\r\n<\/section>\r\n<section class=\"textbox keyTakeaway\">\r\n<div>\r\n<h3>experimental unit<\/h3>\r\n\r\nThe single object or individual to be measured in the experiment is called an\u00a0<strong>experimental unit<\/strong>. The experimental units of the whole experiment are split into two groups:<\/div>\r\n<ul>\r\n\t<li>One group receives the treatment of interest (this is usually called the <strong>experimental group<\/strong>) and the other group does not.<\/li>\r\n\t<li>The group that does not receive the treatment of interest or the placebo is the <strong>control group<\/strong>.<\/li>\r\n<\/ul>\r\n<\/section>\r\n<section class=\"textbox tryIt\">[ohm2_question hide_question_numbers=1]720[\/ohm2_question]<\/section>\r\n<section><\/section>\r\n<section>\r\n<section class=\"textbox keyTakeaway\">\r\n<h3>placebo effect<\/h3>\r\n<p>The <strong>placebo effect<\/strong> is a positive response from people who believe they are receiving treatment for a condition when they are actually receiving a placebo.<\/p>\r\n<p>&nbsp;<\/p>\r\n<p>The placebo effect can make it difficult to gauge the effects on the response variable. It is a fascinating connection between mind and body that is still not completely understood.<\/p>\r\n<\/section>\r\n<\/section>\r\n<section class=\"textbox tryIt\">[ohm2_question hide_question_numbers=1]721[\/ohm2_question]<\/section>","rendered":"<section class=\"textbox learningGoals\">\n<ul>\n<li>Review an experiment and explain if it has been designed well<\/li>\n<li>Use randomized block design to create a hypothetical experiment to answer a research question<\/li>\n<\/ul>\n<\/section>\n<h2>Well-Designed Experiments<\/h2>\n<p>The primary goal of an\u00a0experiment\u00a0is to provide evidence for a cause-and-effect relationship between two variables.<\/p>\n<section class=\"textbox recall\">\n<ul>\n<li><strong>Factor of interest:<\/strong> The explanatory variable (independent variable), which is what we suspect has an effect on the response variable.<\/li>\n<li><strong>Response factor\/variable:<\/strong> The dependent variable, which we suspect is affected by the factor of interest.<\/li>\n<\/ul>\n<\/section>\n<section class=\"textbox tryIt\"><iframe loading=\"lazy\" id=\"ohm719\" class=\"resizable\" src=\"https:\/\/ohm.one.lumenlearning.com\/multiembedq.php?id=719&theme=lumen&iframe_resize_id=ohm719&source=tnh\" width=\"100%\" height=\"150\"><\/iframe><\/section>\n<p>In an experiment, the researcher manipulates values of the explanatory variable and measures the resulting changes in the response variable. The different values of the explanatory variable are called\u00a0<strong>treatments<\/strong>.<\/p>\n<section class=\"textbox keyTakeaway\">\n<div>\n<h3>treatments<\/h3>\n<p><strong>Treatments <\/strong>are experimental conditions into which the participants are divided, some into a group receiving the treatment of interest and others into a control group that does not receive the treatment (a placebo). <\/p>\n<p>A <strong>placebo<\/strong>\u00a0is a harmless version of the treatment that does not contain any active ingredients (e.g., a sugar pill).\u00a0The placebo will typically look, taste, and smell like the treatment of interest or mimic it so that the two treatments appear identical to the subjects; this way the subjects don\u2019t know which treatment they are receiving.<\/div>\n<\/section>\n<section class=\"textbox keyTakeaway\">\n<div>\n<h3>experimental unit<\/h3>\n<p>The single object or individual to be measured in the experiment is called an\u00a0<strong>experimental unit<\/strong>. The experimental units of the whole experiment are split into two groups:<\/div>\n<ul>\n<li>One group receives the treatment of interest (this is usually called the <strong>experimental group<\/strong>) and the other group does not.<\/li>\n<li>The group that does not receive the treatment of interest or the placebo is the <strong>control group<\/strong>.<\/li>\n<\/ul>\n<\/section>\n<section class=\"textbox tryIt\"><iframe loading=\"lazy\" id=\"ohm720\" class=\"resizable\" src=\"https:\/\/ohm.one.lumenlearning.com\/multiembedq.php?id=720&theme=lumen&iframe_resize_id=ohm720&source=tnh\" width=\"100%\" height=\"150\"><\/iframe><\/section>\n<section><\/section>\n<section>\n<section class=\"textbox keyTakeaway\">\n<h3>placebo effect<\/h3>\n<p>The <strong>placebo effect<\/strong> is a positive response from people who believe they are receiving treatment for a condition when they are actually receiving a placebo.<\/p>\n<p>&nbsp;<\/p>\n<p>The placebo effect can make it difficult to gauge the effects on the response variable. It is a fascinating connection between mind and body that is still not completely understood.<\/p>\n<\/section>\n<\/section>\n<section class=\"textbox tryIt\"><iframe loading=\"lazy\" id=\"ohm721\" class=\"resizable\" src=\"https:\/\/ohm.one.lumenlearning.com\/multiembedq.php?id=721&theme=lumen&iframe_resize_id=ohm721&source=tnh\" width=\"100%\" height=\"150\"><\/iframe><\/section>\n","protected":false},"author":13,"menu_order":14,"template":"","meta":{"_candela_citation":"[]","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"part":743,"module-header":"learn_it","content_attributions":[],"internal_book_links":[],"video_content":null,"cc_video_embed_content":{"cc_scripts":"","media_targets":[]},"try_it_collection":null,"_links":{"self":[{"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/pressbooks\/v2\/chapters\/764"}],"collection":[{"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/wp\/v2\/users\/13"}],"version-history":[{"count":10,"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/pressbooks\/v2\/chapters\/764\/revisions"}],"predecessor-version":[{"id":7059,"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/pressbooks\/v2\/chapters\/764\/revisions\/7059"}],"part":[{"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/pressbooks\/v2\/parts\/743"}],"metadata":[{"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/pressbooks\/v2\/chapters\/764\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/wp\/v2\/media?parent=764"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/pressbooks\/v2\/chapter-type?post=764"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/wp\/v2\/contributor?post=764"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/content.one.lumenlearning.com\/introstatstest\/wp-json\/wp\/v2\/license?post=764"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}