Penelitian ini bertujuan untuk menghasilkan LKPD berbasis strategi metakognitif know-learned (K-L) pada materi virus untuk melatihkan keterampilan metakognitif yang valid, praktis, dan efektif. Selain itu, penelitian ini juga bertujuan untuk mendeskripsikan kelayakan LKPD berdasarkan validitas, kepraktisan, dan keefektifan LKPD. Penelitian dilakukan pada bulan Juli 2018 s.d. Januari 2019 bertempat di Jurusan Biologi, FMIPA, Unesa dan diujicobakan secara terbatas di SMAN 4 Sidoarjo. Penelitian ini adalah penelitian pengembangan yang mengacu pada model pengembangan 4-D tanpa tahapan disseminate. Data dikumpulkan menggunakan metode validasi, observasi, angket, tes, dan penilaian diri. Validitas diukur berdasasarkan penilaian ahli, kepraktisan diukur berdasarkan keterlaksanaan LKPD dan respons peserta didik, serta keefektifan diukur berdasarkan ketuntasan indikator, peningkatan hasil belajar, dan keterampilan metakognitif. Hasil validasi menunjukkan bahwa LKPD dan soal pretest-posttest dinilai sangat valid dengan skor validasi sebesar 4,00. LKPD dinyatakan sangat praktis berdasarkan pengamatan keterlaksanaan pembelajaran dengan persentase keterlaksanaan sebesar 100% dan persentase respons peserta didik sebesar 97,46%. LKPD dinilai sangat efektif dalam melatihkan keterampilan metakognitif peserta didik dengan perolehan skor rata-rata metakognitif sebesar 3,93 kategori sangat baik. LKPD juga dinyatakan sangat efektif dengan perolehan sensitivitas positif pada kisaran 0,3-1,0. Selain itu LKPD juga dinyatakan sangat efektif dalam meningkatkan hasil belajar 93,33% peserta didik dengan kriteria tinggi dan 6,67% peserta didik dengan kategori sedang. Dengan demikian LKPD berbasis strategi metakognitif K-L pada materi virus dinyatakan sangat valid, praktis, dan efektif untuk digunakan dalam pembelajaran.
The purpose of this research was to produce a valid, practical, and effective student worksheet based on Know-Learned (K-L) metacognitive strategy on virus material topic to train metacognitive skill. In addition, this study also aimed to describe the eligibility of student worksheet based on the validity, practicality, and effectiveness of student worksheet. This research which had been held from July 2018 to January 2019 in Biology Department, FMIPA, Unesa and limited implemented in SMAN 4 Sidoarjo. This study was a development research which was referred to 4-D model without disseminate stage. Data collected using validation, observation, questionnaire, test, and self-assessment methods. The validity reffered based on expert validation, practically based on student worksheet implementation and student’s responses, and effectiveness based on sensitivity, gain score, and metacognitive skill. The validation result showed that the student worksheet and pretest-posttest were properly with the value of 4,00. Student worksheet was practicable for biology learning based on student worksheet implementation with the value of 100% and student’s responses with the value of 97,46%. Student worksheet was effective to train student’s metacognitive skills with the value of 3,93 (very good category). Student worksheet was also effective with positive sensitivity in the range of 0,3-1,0. In addition, student worksheet was also effective to gain learning outcomes of 93,33% students with the high criteria and 6,67% student with the medium criteria. Therefore, Student worksheet based on Know-Learned (K-L) metacognitive strategy on virus material topic was valid, practical, and effective to be used in learning activities.