How long to run an A/B test for?

One of the most common source of false results when doing A/B testing is to stop your tests too early or in the middle of a business cycle. If you do that, your results will most likely be off, sometimes by a small margin, sometimes by an order of magnitude....

The maths behind the minimum sample size in A/B testing

[fusion_builder_container hundred_percent="yes" overflow="visible"][fusion_builder_row][fusion_builder_column type="1_1" background_position="left top" background_color="" border_size="" border_color="" border_style="solid" spacing="yes" background_image="" background_repeat="no-repeat" padding="" margin_top="0px" margin_bottom="0px" class="" id="" animation_type="" animation_speed="0.3" animation_direction="left" hide_on_mobile="no" center_content="no" min_height="none"][latexpage] This post explains in detail the parameters and maths behind the online calculators available on this website: the A/B testing strategy planning calculator and the A/B...

How to best use the Optimizely free plan (Starter)?

[fusion_builder_container hundred_percent="yes" overflow="visible"][fusion_builder_row][fusion_builder_column type="1_1" background_position="left top" background_color="" border_size="" border_color="" border_style="solid" spacing="yes" background_image="" background_repeat="no-repeat" padding="" margin_top="0px" margin_bottom="0px" class="" id="" animation_type="" animation_speed="0.3" animation_direction="left" hide_on_mobile="no" center_content="no" min_height="none"][fusion_alert type="general" accent_color="" background_color="" border_size="1px" icon="fa-refresh" box_shadow="yes" animation_type="0" animation_direction="down" animation_speed="0.1" class="" id=""]Last updated: November 24, 2014.[/fusion_alert] Optimizely new Free plan: 50,000 unique visitors a month included Optimizely...

Why your Google Analytics data differs from your A/B testing data?

[fusion_builder_container hundred_percent="yes" overflow="visible"][fusion_builder_row][fusion_builder_column type="1_1" background_position="left top" background_color="" border_size="" border_color="" border_style="solid" spacing="yes" background_image="" background_repeat="no-repeat" padding="" margin_top="0px" margin_bottom="0px" class="" id="" animation_type="" animation_speed="0.3" animation_direction="left" hide_on_mobile="no" center_content="no" min_height="none"][latexpage] Often times, when running your first A/B tests, you will notice that the data given by your testing tool differs, sometimes markedly, from the data you...

Why you shouldn’t run multiple A/B tests at the same time

[fusion_builder_container hundred_percent="yes" overflow="visible"][fusion_builder_row][fusion_builder_column type="1_1" background_position="left top" background_color="" border_size="" border_color="" border_style="solid" spacing="yes" background_image="" background_repeat="no-repeat" padding="" margin_top="0px" margin_bottom="0px" class="" id="" animation_type="" animation_speed="0.3" animation_direction="left" hide_on_mobile="no" center_content="no" min_height="none"][fusion_alert type="general" accent_color="" background_color="" border_size="1px" icon="" box_shadow="yes" animation_type="0" animation_direction="down" animation_speed="0.1" class="" id=""]Last updated: October 16, 2014.[/fusion_alert] [/fusion_builder_column][fusion_builder_column type="1_1" background_position="left top" background_color="" border_size="" border_color="" border_style="solid" spacing="yes" background_image="" background_repeat="no-repeat"...